Here is,

I. A law to preserve the honour of the marriage-bed, that it should not be unseasonably used (Lev. 18:19), nor invaded by an adulterer, Lev. 18:20.

II. A law against that which was the most unnatural idolatry, causing their children to pass through the fire to Moloch, Lev. 18:21. Moloch (as some think) was the idol in and by which they worshipped the sun, that great fire of the world; and therefore in the worship of it they made their own children either sacrifices to this idol, burning them to death before it, or devotees to it, causing them to pass between two fires, as some think, or to be thrown through one, to the honour of this pretended deity, imagining that the consecrating of but one of their children in this manner to Moloch would procure good fortune for all the rest of their children. Did idolaters thus give their own children to false gods, and shall we think any thing too dear to be dedicated to, or to be parted with for, the true God? See how this sin of Israel (which they were afterwards guilty of, notwithstanding this law) is aggravated by the relation which they and their children stood in to God. Ezek. 16:20; Thou hast taken thy sons and thy daughters, whom thou hast borne unto me, and these thou hast sacrificed. Therefore it is here called profaning the name of their God; for it looked as if they thought they were under greater obligations to Moloch than to Jehovah; for to him they offered their cattle only, but to Moloch their children.

III. A law against unnatural lusts, sodomy and bestiality, sins not to be named nor thought of without the utmost abhorrence imaginable, Lev. 18:22, 23. Other sins level men with the beasts, but these sink them much lower. That ever there should have been occasion for the making of these laws, and that since they are published they should ever have been broken, is the perpetual reproach and scandal of human nature; and the giving of men up to these vile affections was frequently the punishment of their idolatries; so the apostle shows, Rom. 1:24.

IV. Arguments against these and the like abominable wickednesses. He that has an indisputable right to command us, yet because he will deal with us as men, and draw with the cords of a man, condescends to reason with us.

1. Sinners defile themselves with these abominations: Defile not yourselves in any of these things, Lev. 18:24. All sin is defiling to the conscience, but these are sins that have a peculiar turpitude in them. Our heavenly Father, in kindness to us, requires of us that we keep ourselves clean, and do not wallow in the dirt.
2. The souls that commit them shall be cut off, Lev. 18:29. And justly; for, if any man defile the temple of God, him shall God destroy, 1 Cor. 3:17. Fleshly lusts war against the soul, and will certainly be the ruin of it if God’s mercy and grace prevent not.
3. The land is defiled, Lev. 18:25. If such wickednesses as these be practised and connived at, the land is thereby made unfit to have God’s tabernacle in it, and the pure and holy God will withdraw the tokens of his gracious presence from it. It is also rendered unwholesome to the inhabitants, who are hereby infected with sin and exposed to plagues and it is really nauseous and loathsome to all good men in it, as the wickedness of Sodom was to the soul of righteous Lot.
4. These have been the abominations of the former inhabitants, Lev. 18:24, 27. Therefore it was necessary that these laws should be made, as antidotes and preservatives from the plague are necessary when we go into an infected place. And therefore they should not practise any such things, because the nations that had practised them now lay under the curse of God, and were shortly to fall by the sword of Israel. They could not but be sensible how odious those people had made themselves who wallowed in this mire, and how they stank in the nostrils of all good men; and shall a people sanctified and dignified as Israel was make themselves thus vile? When we observe how ill sin looks in others we should use this as an argument with ourselves with the utmost care and caution to preserve our purity.
5. For these and the like sins the Canaanites were to be destroyed; these filled the measure of the Amorites’ iniquity (Gen. 15:16), and brought down that destruction of so many populous kingdoms which the Israelites were now shortly to be not only the spectators, but the instruments of: Therefore I do visit the iniquity thereof upon it, Lev. 18:25. Note, The tremendous judgments of God, executed on those that are daringly profane and atheistical, are intended as warnings to those who profess religion to take heed of every thing that has the least appearance of, or tendency towards, profaneness or atheism. Even the ruin of the Canaanites is an admonition to the Israelites not to do like them. Nay, to show that not only the Creator is provoked, but the creation burdened, by such abominations as these, it is added (Lev. 18:25), The land itself vomiteth out her inhabitants. The very ground they went upon did, as it were, groan under them, and was sick of them, and not easy till it had discharged itself of these enemies of the Lord, Isa. 1:24. This bespeaks the extreme loathsomeness of sin; sinful man indeed drinks in iniquity like water, but the harmless part of the creation even heaves at it, and rises against it. Many a house and many a town have spued out the wicked inhabitants, as it were, with abhorrence, Rev. 3:16. Therefore take heed, saith God, that the land spue not you out also, Lev. 18:28. It was secured to them, and entailed upon them, and yet they must expect that, if they made the vices of the Canaanites their own, with their land their fate would be the same. Note, Wicked Israelites are as abominable to God as wicked Canaanites, and more so, and will be as soon spued out, or sooner. Such a warning as was here given to the Israelites is given by the apostle to the Gentile converts, with reference to the rejected Jews, in whose room they were substituted (Rom. 11:19); they must take heed of falling after the same example of unbelief, Heb. 4:11. Apply it more generally; and let it deter us effectually from all sinful courses to consider how many they have been the ruin of. Lay the ear of faith to the gates of the bottomless pit, and hear the doleful shrieks and outcries of damned sinners, whom earth has spued out and hell has swallowed, that find themselves undone, for ever undone, by sin; and tremble lest this be your portion at last. God’s threatenings and judgments should frighten us from sin.

V. The chapter concludes with a sovereign antidote against this infection: Therefore you shall keep my ordinance that you commit not any one of these abominable customs, Lev. 18:30. This is the remedy prescribed. Note,

1. Sinful customs are abominable customs, and their being common and fashionable does not make them at all the less abominable nor should we the less abominate them, but the more; because the more customary they are the more dangerous they are.
2. It is of pernicious consequence to admit and allow of any one sinful custom, because one will make way for many, Uno absurdo dato, mille sequuntur—Admit but a single absurdity, you invite a thousand. The way of sin is downhill.
3. A close and constant adherence to God’s ordinances is the most effectual preservative from the infection of gross sin. The more we taste of the sweetness and feel of the power of holy ordinances the less inclination we shall have to the forbidden pleasures of sinners’ abominable customs. It is the grace of God only that will secure us, and that grace is to be expected only in the use of the means of grace. Nor does God ever leave any to their own hearts’ lusts till they have first left him and his institutions.

———

Taken from Matthew Henry’s Commentary (Complete).