Thou shalt not {k} commit adultery.

(k) But be pure in heart, word and deed.

Wesley's Notes

20:14 Thou shalt not commit adultery - This commandment forbids all acts of uncleanness, with all those desires, which produce those acts and war against the soul.

Matthew Henry's Concise Commentary

20:12-17 The laws of the SECOND table, that is, the last six of the ten commandments, state our duty to ourselves and to one another, and explain the great commandment, Thou shalt love thy neighbour as thyself, Lu 10:27. Godliness and honesty must go together. The fifth commandment concerns the duties we owe to our relations. Honour thy father and thy mother, includes esteem of them, shown in our conduct; obedience to their lawful commands; come when they call you, go where they send you, do what they bid you, refrain from what they forbid you; and this, as children, cheerfully, and from a principle of love. Also submission to their counsels and corrections. Endeavouring, in every thing, to comfort parents, and to make their old age easy; maintaining them if they need support, which our Saviour makes to be particularly intended in this commandment, Mt 15:4-6. Careful observers have noted a peculiar blessing in temporal things on obedient, and the reverse on disobedient children. The sixth commandment requires that we regard the life and the safety of others as we do our own. Magistrates and their officers, and witnesses testifying the truth, do not break this command. Self-defence is lawful; but much which is not deemed murder by the laws of man, is such before God. Furious passions, stirred up by anger or by drunkenness, are no excuse: more guilty is murder in duels, which is a horrible effect of a haughty, revengeful spirit. All fighting, whether for wages, for renown, or out of anger and malice, breaks this command, and the bloodshed therein is murder. To tempt men to vice and crimes which shorten life, may be included. Misconduct, such as may break the heart, or shorten the lives of parents, wives, or other relatives, is a breach of this command. This command forbids all envy, malice, hatred, or anger, all provoking or insulting language. The destruction of our own lives is here forbidden. This commandment requires a spirit of kindness, longsuffering, and forgiveness. The seventh commandment concerns chastity. We should be as much afraid of that which defiles the body, as of that which destroys it. Whatever tends to pollute the imagination, or to raise the passions, falls under this law, as impure pictures, books, conversation, or any other like matters. The eighth commandment is the law of love as it respects the property of others. The portion of worldly things allotted us, as far as it is obtained in an honest way, is the bread which God hath given us; for that we ought to be thankful, to be contented with it, and, in the use of lawful means, to trust Providence for the future. Imposing upon the ignorance, easiness, or necessity of others, and many other things, break God's law, though scarcely blamed in society. Plunderers of kingdoms though above human justice, will be included in this sentence. Defrauding the public, contracting debts without prospect of paying them, or evading payment of just debts, extravagance, all living upon charity when not needful, all squeezing the poor in their wages; these, and such things, break this command; which requires industry, frugality, and content, and to do to others, about worldly property, as we would they should do to us. The ninth commandment concerns our own and our neighbour's good name. This forbids speaking falsely on any matter, lying, equivocating, and any way devising or designing to deceive our neighbour. Speaking unjustly against our neighbour, to hurt his reputation. Bearing false witness against him, or in common conversation slandering, backbiting, and tale-bearing; making what is done amiss, worse than it is, and in any way endeavouring to raise our reputation upon the ruin of our neighbour's. How much this command is every day broken among persons of all ranks! The tenth commandment strikes at the root; Thou shalt not covet. The others forbid all desire of doing what will be an injury to our neighbour; this forbids all wrong desire of having what will gratify ourselves.

Matthew Henry's Whole Bible Commentary

Verses 12-17

We have here the laws of the second table, as they are commonly called, the last six of the ten commandments, comprehending our duty to ourselves and to one another, and constituting a comment upon the second great commandment, Thou shalt love thy neighbour as thyself. As religion towards God is an essential branch of universal righteousness, so righteousness towards men is an essential branch of true religion. Godliness and honesty must go together.

I. The fifth commandment concerns the duties we owe to our relations; those of children to their parents are alone specified: Honour thy father and thy mother, which includes, 1. A decent respect to their persons, an inward esteem of them outwardly expressed upon all occasions in our conduct towards them. Fear them (Lev. 19:3), give them reverence, Heb. 12:9. The contrary to this is mocking at them and despising them, Prov. 30:17. 2. Obedience to their lawful commands; so it is expounded (Eph. 6:1-3): "Children, obey your parents, come when they call you, go where they send you, do what they bid you, refrain from what they forbid you; and this, as children, cheerfully, and from a principle of love." Though you have said, "We will not," yet afterwards repent and obey, Mt. 21:29. 3. Submission to their rebukes, instructions, and corrections; not only to the good and gentle, but also to the froward, out of conscience towards God. 4. Disposing of themselves with the advice, direction, and consent, of parents, not alienating their property, but with their approbation. 5. Endeavouring, in every thing, to be the comfort of their parents, and to make their old age easy to them, maintaining them if they stand in need of support, which our Saviour makes to be particularly intended in this commandment, Mt. 15:4-6. The reason annexed to this commandment is a promise: That thy days may be long in the land which the Lord thy God giveth thee. Having mentioned, in the preface to the commandments, has bringing them out of Egypt as a reason for their obedience, he here, in the beginning of the second table, mentions his bringing them into Canaan, as another reason; that good land they must have upon their thoughts and in their eye, now that they were in the wilderness. They must also remember, when they came to that land, that they were upon their good behaviour, and that, if they did not conduct themselves well, their days should be shortened in that land, both the days of particular persons who should be cut off from it, and the days of their nation which should be removed out of it. But here a long life in that good land is promised particularly to obedient children. Those that do their duty to their parents are most likely to have the comfort of that which their parents gather for them and leave to them; those that support their parents shall find that God, the common Father, will support them. This promise is expounded (Eph. 6:3), That it may be well with thee, and thou mayest live long on the earth. Those who, in conscience towards God, keep this and the rest of God's commandments, may be sure that it shall be well with them, and that they shall live as long on earth as Infinite Wisdom sees good for them, and that what they may seem to be cut short of on earth shall be abundantly made up in eternal life, the heavenly Canaan which God will give them.

II. The sixth commandment concerns our own and our neighbour's life (v. 13): "Thou shalt not kill; thou shalt not do any thing hurtful or injurious to the health, ease, and life, of thy own body, or any other person's unjustly." This is one of the laws of nature, and was strongly enforced by the precepts given to Noah and his sons, Gen. 9:5, 6. It does not forbid killing in lawful war, or in our own necessary defence, nor the magistrate's putting offenders to death, for those things tend to the preserving of life; but it forbids all malice and hatred to the person of any (for he that hateth his brother is a murderer), and all personal revenge arising therefrom; also all rash anger upon sudden provocations, and hurt said or done, or aimed to be done, in passion: of this our Saviour expounds this commandment, Mt. 5:22. And, as that which is worst of all, it forbids persecution, laying wait for the blood of the innocent and excellent ones of the earth.

III. The seventh commandment concerns our own and our neighbour's chastity: Thou shalt not commit adultery, v. 14. This is put before the sixth by our Saviour (Mk. 10:19): Do not commit adultery, do not kill; for our chastity should be as dear to us as our lives, and we should be as much afraid of that which defiles the body as of that which destroys it. This commandment forbids all acts of uncleanness, with all those fleshly lusts which produce those acts and war against the soul, and all those practices which cherish and excite those fleshly lusts, as looking, in order to lust, which, Christ tells us, is forbidden in this commandment, Mt. 5:28.

IV. The eighth commandment concerns our own and our neighbour's wealth, estate, and goods: Thou shalt not steal, v. 15. Though God had lately allowed and appointed them to spoil the Egyptians in a way of just reprisal, yet he did not intend that it should be drawn into a precedent and that they should be allowed thus to spoil one another. This command forbids us to rob ourselves of what we have by sinful spending, or of the use and comfort of it by sinful sparing, and to rob others by removing the ancient landmarks, invading our neighbour's rights, taking his goods from his person, or house, or field, forcibly or clandestinely, over-reaching in bargains, nor restoring what is borrowed or found, withholding just debts, rents, or wages, and (which is worst of all) to rob the public in the coin or revenue, or that which is dedicated to the service of religion.

V. The ninth commandment concerns our own and our neighbour's good name: Thou shalt not bear false witness, v. 16. This forbids, 1. Speaking falsely in any matter, lying, equivocating, and any way devising and designing to deceive our neighbour. 2. Speaking unjustly against our neighbour, to the prejudice of his reputation; and (which involves the guilty of both), 3. Bearing false witness against him, laying to his charge things that he knows not, either judicially, upon oath (by which the third commandment, and the sixth of eighth, as well as this, are broken), or extrajudicially, in common converse, slandering, backbiting, tale-bearing, aggravating what is done amiss and making it worse than it is, and any way endeavouring to raise our own reputation upon the ruin of our neighbour's.

VI. The tenth commandment strikes at the root: Thou shalt not covet, v. 17. The foregoing commands implicitly forbid all desire of doing that which will be an injury to our neighbour; this forbids all inordinate desire of having that which will be a gratification to ourselves. "O that such a man's house were mine! Such a man's wife mine! Such a man's estate mine!" This is certainly the language of discontent at our own lot, and envy at our neighbour's; and these are the sins principally forbidden here. St. Paul, when the grace of God caused the scales to fall from his eyes, perceived that this law, Thou shalt not covet, forbade all those irregular appetites and desires which are the first-born of the corrupt nature, the first risings of the sin that dwelleth in us, and the beginnings of all the sin that is committed by us: this is that lust which, he says, he had not known the evil of, if this commandment, when it came to his conscience in the power of it, had not shown it to him, Rom. 7:7. God give us all to see our face in the glass of this law, and to lay our hearts under the government of it!