The Larger Catechism
99. Q. What rules are to be observed for the right understanding of the ten commandments?
A. For the right understanding of the ten commandments, these rules are to be observed:
- That the law is perfect, and bindeth everyone to full conformity in the whole man unto the righteousness thereof, and unto entire obedience forever; so as to require the utmost perfection of every duty, and to forbid the least degree of every sin.
- That it is spiritual, and so reacheth the understanding, will, affections, and all other powers of the soul; as well as words, works, and gestures.
- That one and the same thing, in divers respects, is required or forbidden in several commandments.
- That as, where a duty is commanded, the contrary sin is forbidden; and, where a sin is forbidden, the contrary duty is commanded: so, where a promise is annexed, the contrary threatening is included; and, where a threatening is annexed, the contrary promise is included.
- That what God forbids, is at no time to be done; what he commands, is always our duty; and yet every particular duty is not to be done at all times.
- That under one sin or duty, all of the same kind are forbidden or commanded; together with all the causes, means, occasions, and appearances thereof, and provocations thereunto.
- That what is forbidden or commanded to ourselves, we are bound, according to our places to endeavour that it may be avoided or performed by others, according to the duty of their places.
- That in what is commanded to others, we are bound, according to our places and callings, to be helpful to them; and to take heed of partaking with others in what is forbidden them.
Scriptural Defense and Commentary
 Psalm 19:7. The law of the LORD is perfect, converting the soul: the testimony of the LORD is sure, making wise the simple. James 2:10. For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all. Matthew 5:21-22. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.  Romans 7:14. For we know that the law is spiritual: but I am carnal, sold under sin. Deuteronomy 6:5. And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might. Matthew 22:37-39. Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. Matthew 5:21-22, 27-28, 33-34, 37-39, 43-44. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire…. Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart…. Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: But I say unto you, Swear not at all; neither by heaven; for it is God’s throne…. But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil. Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also…. Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you.  Colossians 3:5. Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry. Amos 8:5. Saying, When will the new moon be gone, that we may sell corn? and the sabbath, that we may set forth wheat, making the ephah small, and the shekel great, and falsifying the balances by deceit? Proverbs 1:19. So are the ways of every one that is greedy of gain; which taketh away the life of the owners thereof. 1 Timothy 6:10. For the love of money is the root of all evil: which while some coveted after, they have erred from the faith, and pierced themselves through with many sorrows.  Isaiah 58:13. If thou turn away thy foot from the sabbath, from doing thy pleasure on my holy day; and call the sabbath a delight, the holy of the LORD, honourable; and shalt honour him, not doing thine own ways, nor finding thine own pleasure, nor speaking thine own words. Deuteronomy 6:13. Thou shalt fear the LORD thy God, and serve him, and shalt swear by his name. Matthew 4:9-10. And saith unto him, All these things will I give thee, if thou wilt fall down and worship me. Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. Matthew 15:4-6. For God commanded, saying, Honour thy father and mother: and, He that curseth father or mother, let him die the death. But ye say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou mightest be profited by me; And honour not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition.  Matthew 5:21-25. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire. Therefore if thou bring thy gift to the altar, and there rememberest that thy brother hath ought against thee; Leave there thy gift before the altar, and go thy way; first be reconciled to thy brother, and then come and offer thy gift. Agree with thine adversary quickly, whiles thou art in the way with him; lest at any time the adversary deliver thee to the judge, and the judge deliver thee to the officer, and thou be cast into prison. Ephesians 4:28. Let him that stole steal no more: but rather let him labour, working with his hands the thing which is good, that he may have to give to him that needeth.  Exodus 20:12. Honour thy father and thy mother: that thy days may be long upon the land which the LORD thy God giveth thee. Proverbs 30:17. The eye that mocketh at his father, and despiseth to obey his mother, the ravens of the valley shall pick it out, and the young eagles shall eat it.  Jeremiah 18:7-8. At what instant I shall speak concerning a nation, and concerning a kingdom, to pluck up, and to pull down, and to destroy it; If that nation, against whom I have pronounced, turn from their evil, I will repent of the evil that I thought to do unto them. Exodus 20:7. Thou shalt not take the name of the LORD thy God in vain; for the LORD will not hold him guiltless that taketh his name in vain. Psalm 15:1, 4-5. LORD, who shall abide in thy tabernacle? who shall dwell in thy holy hill?… In whose eyes a vile person is contemned; but he honoureth them that fear the LORD. He that sweareth to his own hurt, and changeth not. He that putteth not out his money to usury, nor taketh reward against the innocent. He that doeth these things shall never be moved. Psalm 24:4-5. He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully. He shall receive the blessing from the LORD, and righteousness from the God of his salvation.  Job 13:7-8. Will ye speak wickedly for God? and talk deceitfully for him? Will ye accept his person? will ye contend for God? Romans 3:8. And not rather, (as we be slanderously reported, and as some affirm that we say,) Let us do evil, that good may come? whose damnation is just. Job 36:21. Take heed, regard not iniquity: for this hast thou chosen rather than affliction. Hebrews 11:25. Choosing rather to suffer affliction with the people of God, than to enjoy the pleasures of sin for a season.  Deuteronomy 4:8-9. And what nation is there so great, that hath statutes and judgments so righteous as all this law, which I set before you this day? Only take heed to thyself, and keep thy soul diligently, lest thou forget the things which thine eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them thy sons, and thy sons’ sons.  Matthew 12:7. But if ye had known what this meaneth, I will have mercy, and not sacrifice, ye would not have condemned the guiltless.  Matthew 5:21-22, 27-28. Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire…. Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. Matthew 15:4-6. For God commanded, saying, Honour thy father and mother: and, He that curseth father or mother, let him die the death. But ye say, Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou mightest be profited by me; And honour not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition. Hebrews 10:24-25. And let us consider one another to provoke unto love and to good works: Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching. 1 Thessalonians 5:22. Abstain from all appearance of evil. Jude 23. And others save with fear, pulling them out of the fire; hating even the garment spotted by the flesh. Galatians 5:26. Let us not be desirous of vain glory, provoking one another, envying one another. Colossians 3:21. Fathers, provoke not your children to anger, lest they be discouraged.  Exodus 20:10. But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates. Leviticus 19:17. Thou shalt not hate thy brother in thine heart: thou shalt in any wise rebuke thy neighbour, and not suffer sin upon him. Genesis 18:19. For I know him, that he will command his children and his household after him, and they shall keep the way of the LORD, to do justice and judgment; that the LORD may bring upon Abraham that which he hath spoken of him. Joshua 14:15. And the name of Hebron before was Kirjatharba; which Arba was a great man among the Anakims. And the land had rest from war. Deuteronomy 6:6-7. And these words, which I command thee this day, shall be in thine heart: And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up.  2 Corinthians 1:24. Not for that we have dominion over your faith, but are helpers of your joy: for by faith ye stand.  1 Timothy 5:22. Lay hands suddenly on no man, neither be partaker of other men’s sins: keep thyself pure. Ephesians 5:11. And have no fellowship with the unfruitful works of darkness, but rather reprove them.
A most superficial understanding of God’s law often prevails in our hearts (especially as believers). A child might take his parent’s instruction in different ways. When told to clean his room, he might pick up everything off the floor. Dusting, vacuuming, making his bed, folding his clothes, tidying up his bookshelf, etc. may not enter his mind. Furthermore, if he was called to the table to eat dinner, then may he assume that the previous request has been voided? Perhaps he was intending to do it after dinner but he forgot? Can he declare his innocence because he did not forget on purpose nor did he forget with ill intent? After all, he is only human.
Did the boy comply with his parent’s request? Many factors and conditions come into play. Now, looking at the LC answer, one may think the answer is cumbersomely detailed and even too clever by a half. But do we not often seel to justify ourselves? Coming back to the boy, could not he exclaim, “You didn’t specify?” “I took your command to mean only that I pick up the big pieces on the floor!” Would we say he obeyed if he screamed, convulsed in anger while crying and then after five hours in bitterness and defiance “cleaned” the room? Did he obey? Were his parents pleased? This small event reveals some of the complexities involved in our own affairs.
When we come to applying God’s law to our lives, we can easily act like the little boy. Did President Clinton commit adultery? If we maimed someone without actually killing him, did we actually murder? If not, then have I fulfilled that commandment? The divines understood quite well the subtle reasonings of our hearts. For that reason, they offered some guiding principles.
Before unpacking the eight ways of understanding the Ten Commandments, let us dispense with an objection that may come up. Are not these rules arbitrary? Why not ten ways of understanding the Ten Commandments? Why not five? These general principles emerge from the nature of God’s law. That is, they logically and necessarily flow from the nature of God’s law. Did God have to write individual laws about every conceivable event? Could He not command a few laws that could logically and necessarily address a great many of particulars, contingencies, etc.? Yes He could and we maintain that He did. We hope to see this played out in the upcoming studies of the commandments. Furthermore, the divines were driven to these “rules” because of the way our Lord interpreted God’s law.
If the Ten Commandments are a “comprehensive summary” of God’s moral law then it stands to reason that we should be able to unpack its comprehensive implications (cf. Vos). These eight rules help us to see the law’s implications.
Rule 1: Full Conformity and Utmost Perfection
This rule can be summarized as, “God’s law is perfect and we must obey it perfectly.” The first part of the sentence reads, “That the law is perfect, and bindeth everyone to full conformity in the whole man unto the righteousness thereof, and unto entire obedience forever…” Because God’s law is perfect (Ps. 19:7), it follows we who have to obey (which includes everyone) fully. “Full conformity” means complete conformity to the righteous demands of that law. Our fully conformity must be perpetual — “unto entire obedience forever.” God did not give His perfect law so that we can obey it partially. The Lord of the universe, our Creator requires that we be in full conformity and that perpetually. In Ezekiel 20:19 God says, “I am the LORD your God; walk in my statutes, and be careful to obey my rules [literally, “keep and do them”], and keep my Sabbaths holy…” God did not give His statutes to be disregarded but kept and obeyed.
The divines carefully explain what this “entire obedience” entails: “so as to require the utmost perfection of every duty, and to forbid the least degree of every sin.” Our obedience must not be half-hearted or partial. The perfect God who gave His perfect law requires “the utmost perfection of every duty.” James 1:10 is used to support the idea of “utmost perfection of every duty.” James says, “For whoever keeps the whole law but fails in one point has become account for all of it.” The failure in the “one point” [literally, “in one” ἐν ἑνί] probably refers to keeping all the commandments (as v. 11 indicates). Nonetheless, the general thrust of the verse applies. James teaches that we must keep the whole law without failing in one area, that is, we must keep every commandment and perform every duty.
When Jesus explained what the sixth commandment required, he did not merely address the simple notion of murdering. Jesus explained the commandment to include the entire person, namely one’s heart. The commandment to not kill means we cannot be angry with the brother without a cause (Mt. 5:21-22) nor can we call him a fool. That is, the sixth commandment means we can’t hurt the other person’s body nor can we harm them with our words. That is part of that perfection required in the sixth commandment. We should also be able to see what the last phrase “to forbid the least degree of every sin” means. If something is required, then what is forbidden by implication cannot be committed in the least degree (not committing adultery includes loving one’s wife). So, if we cannot kill then we are also forbidden from hurting the person in any other way (like calling him a fool).
Rule 2: Words, Works, and Gestures
We have often performed some duties for friends, acquaintances, etc. with little or no heart. We might visit them, attend their children’s weddings, graduations, etc. out of respect for them and yet in our hearts hate the whole engagement. Probably the most common problem is the way we worship God. We may go through the motions and “honor” God with our lips while keeping our hearts far from him (cf. Is. 29:13; Mt. 15:18). God well knows our hearts and we deceive only ourselves in our religious acts of piety — God is not pleased.
The second rule states, “That it is spiritual, and so reacheth the understanding, will, affections, and all other powers of the soul; as well as words, works, and gestures.” The laws of God are spiritual and have not been given to address only our minds. Has not our Lord taught us that we are to love the Lord our God “with all our heart, and with all our soul, and with all our mind” (Mt. 22:37-39; cf. Deut. 6:5)? The law requires conformity with our understanding, will, affections “and all other powers of the soul.”
God calls us to love Him, obey Him, and to understand Him. We cannot go through the motions in our acts of piety while engaging our affections on a sports team. We must not worship him in private and public reluctantly. Our willing spirit and warm affections must be involved. Ridgley says that our wills should “express a readiness to obey him out of choice, and without the least reluctance…” Vos described the Pharisees as those who
overlooked the spiritual character of the law, and wrongly supposed that it claimed jurisdiction only over their outward conduct. Because of this faulty and partial view of the nature of the moral law, the Pharisees could deceive themselves into thinking that they had attained moral perfection. By a scrupulous observance of the details of the law they thought they had conformed to all its requirements. What they lacked was not outward literal obedience to the precepts and prohibitions of the law, but inward spiritual conformity to its requirements. (Vos)
The last three words denote the active manifestation of the powers of our soul. We express our understanding, will, affections, etc. by our “words, works and gestures.” The law requires we obey it with our words, that is, by what we say, how we speak, etc. Our “works” mean that we manifest the good fruits required by God’s Word. Our gestures, our acts in the body, etc. must conform to God’s law. Lovers of God express their loyalty by the way they handle themselves. Vos says, “the moral law concerns every possible way by which our inward or spiritual life finds expression in the external world which is around us.” Matthew 5:21-22, 27-28, 33-34, 37-39, 43-44 all depict the in depth way our Lord interpreted the law.
Rule 3: Required or Forbidden in Several Commandments
This rule many not appear to be all that perspicuous when you first read it. Yet it may be the simplest of the eight. In short, the same thing could be required or forbidden in more than one commandment: “That one and the same thing, in divers respects, is required or forbidden in several commandments.”
Vos offers a very helpful example on this. “For example, ‘six days shalt thou labor and do all thy work’ is a part of the fourth commandment, relating to the Sabbath; but the eighth commandment, which forbids stealing, also requires a person to work for his living, for the person who lives without working is really stealing his living from someone else.”
The Bible obviously requires the same things in various passages while also forbidding other things in numerous other passages. The passages cited above show this. In Prov. 1:19, greed can lead to the taking of one’s own life: “Such are the ways of everyone who is greedy for unjust gain; it takes away the life of its possessors.” What is forbidden in the eighth commandment (stealing) can also lead to the breaking of the sixth commandment (killing). 1 Timothy 6:10 shows that the breaking of the tenth commandment (coveting) can lead to the departure from the faith (the breaking of the first commandment): “For the love of money is a root of all kinds of evils. It is through this craving that some have wandered away from the faith and pierced themselves with many pangs.” Lastly, Col. 3:5 shows that the breaking of the tenth commandment (coveting) once again leads to idolatry (the breaking of the first and second commandments): “Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry.”
Rule 4: Commanded and Forbidden; Promised and Threatened
The fourth rule should make perfect sense though we do not often think about it. The LC states, “That as, where a duty is commanded, the contrary sin is forbidden; and, where a sin is forbidden, the contrary duty is commanded…” The third commandment forbids the taking of the Lord’s name in vain. While that sin is forbidden, the contrary duty is therefore required: “Thou shalt fear the LORD thy God, and serve him, and shalt swear by his name.” (Deut. 6:13) We are commanded to swear by God’s name. The fourth commandment forbids the misuse of His name, taking His name on our lips for no purpose. But Deuteronomy also commands us to use the Lord name reverently: “swear by his name.” While the seventh commandment forbids adultery, the positive injunction to love our wives can be found in Scripture. Therefore, this fourth rule finds support in Scripture. Vos summarized the fourth rule in these terms:
The catechism teaches that in the Ten Commandments, positive and negative elements imply each other, even though only one or the other is expressly stated. Where a duty is commanded, the contrary sin is forbidden; where a sin is forbidden, it is implied that the contrary duty is commanded; and the same principle applies to the matter of threatenings and promises.
Lastly, with God’s threat comes the contrary, His promises: “and, where a threatening is annexed, the contrary promise is included.” The third commandment comes with a threat: “for the Lord will not hold him guiltless that takes his name in vain” (Ex. 20:7). But we also learn of a promise in Ps. 15. God promises the one “who honors those who fear the Lord” and the one who swears to his own hurt with access to His holy hill (Ps. 15:1, 4). The righteous man was to swear in the Lord’s name and those who swear well will dwell in God’s holy hill, in his tabernacle.
We can draw a very practical point from this first rule. In overcoming personal sins, we should not only look at the sin forbidden. The contrary duty commanded can help us to mortify the sin that is forbidden. For example, the sins forbidden in the seventh commandment can be combatted by pursuing the duties commanded. To illustrate this point, one can better avoid the sin of drunkenness by pursuing wholesome duties. We all know that one must eat healthy foods and exercise while avoiding certain unhealthy meals – both must be pursued. The apostle Paul uses the way of putting off and putting on (Eph. 4:22-24). Nonetheless, true mortification cannot occur merely by avoiding something and doing something else; any moralist can do that.
 On the “binding” nature of God’s moral law, see our study on the LC #93.
 Thomas Ridgley, A Body of Divinity, vol. 2 (New York: Robert Carter & Brothers, 1855), 312.