Sins against the seventh commandment are here ordered to be severely punished. These are sins which, of all others, fools are most apt to make a mock at; but God would teach those the heinousness of the guilt by the extremity of the punishment that would not otherwise be taught it.

I.Lying with another man's wife was made a capital crime. The adulterer and the adulteress that had joined in the sin must fall alike under the sentence: they shall both be put to death, Lev 20:10. Long before this, even in Job's time, this was reputed a heinous crime and an iniquity to be punished by the judges, Job 31:11. It is a presumptuous contempt of an ordinance of God, and a violation of his covenant, Pro 2:17. It is an irreparable wrong to the injured husband, and debauches the mind and conscience of both the offenders as much as any thing. It is a sin which headstrong and unbridled lusts hurry men violently to, and therefore it needs such a powerful restraint as this. It is a sin which defiles a land and brings down God's judgments upon it, which disquiets families, and tends to the ruin of all virtue and religion, and therefore is fit to be animadverted upon by the conservators of the public peace: but see Joh 8:3-11.

II.Incestuous connections, whether by marriage or not. 1. Some of them were to be punished with death, as a man's lying with his father's wife, Lev 20:11. Reuben would have been put to death for his crime (Gen 35:22) if this law had been then made. It was the sin of the incestuous Corinthian, for which he was to be delivered unto Satan, Co1 5:1, Co1 5:5. A man's debauching his daughter-in-law, or his mother-in-law, or his sister, was likewise to be punished with death, Lev 20:12, Lev 20:14, Lev 20:17. 2. Others of them God would punish with the curse of barrenness, as a man's defiling his aunt, or his brother's wife (Lev 20:19-21): They shall die childless. Those that keep not within the divine rules of marriage forfeit the blessings of marriage: They shall commit whoredom, and shall not increase, Hos 4:10. Nay it is said, They shall bear their iniquity, that is, though they be not immediately cut off by the hand either of God or man for this sin, yet the guilt of it shall lie upon them, to be reckoned for another day, and not be purged with sacrifice or offering.

III.The unnatural lusts of sodomy and bestiality (sins not to be mentioned without horror) were to be punished with death, as they are at this day by our law, Lev 20:13, Lev 20:15, Lev 20:16. Even the beast that was thus abused was to be killed with the sinner, who was thereby openly put to the greater shame: and the villany was thus represented as in the highest degree execrable and abominable, all occasions of the remembrance or mention of it being to be taken away. Even the unseasonable use of the marriage, if presumptuous, and in contempt of the law, would expose the offenders to the just judgment of God: they shall be cut off, Lev 20:18. For this is the will of God, that every man should possess his vessel (and the wife is called the weaker vessel) in sanctification and honour, as becomes saints.

If a woman approach unto any beast - We have the authority of one of the most eminent historians in the world, Herodotus, to say that this was a crime not unknown in Egypt; yea, that a case of this nature actually took place while he was there. Εγενετο δ' εν τῳ νο μῳ τουτῳ επ' εμευ τουτο το τερας, Γυναικι Τραγος εμισγετο αναφανδον. Τουτο ες επιδειξιν ανθρωπων απικετο. - Herod. in Euterp., p. 108. Edit. Gale, Lond. 1679.

"In this district, within my own recollection, this portentous business took place: a goat coupled so publicly with a woman that every person knew it," etc. After this, need we wonder that God should have made laws of this nature, when it appears these abominations were not only practiced among the Egyptians, but were parts of a superstitious religious system? This one observation will account for many of those strange prohibitions which we find in the Mosaic law; others, the reasons of which are not so plain, we should see the propriety of equally, had we ampler historic records of the customs that existed in that country.

And if a man shall lie with a woman having her sickness,.... Her monthly courses, which make her weak and languid, which is forbidden, Lev 18:19; this is not to be understood of a man's lying with his wife ignorantly, when in such a condition, for this being the case, he was only unclean seven days, Lev 15:24; whereas this made him and her liable to cutting off, as in an after clause; but of his lying with her, knowing this to be the case with her, and of which she could not be ignorant, and therefore both liable to the same punishment; or else of any other man lying with her, or of any man lying with any woman, married or unmarried, being in such circumstances:

and shall uncover her nakedness; that is, have carnal knowledge of her:

he hath discovered her fountain; from whence her issue of blood flows: and she hath uncovered the fountain of her blood; freely and willingly, as Aben Ezra observes; for if she had been forced, he alone would have been cut off; but both these phrases put together show agreement in this matter, that they both had knowledge of her case, and both consented to commit the sin:

and both of them shall be cut off from among their people; by death, either by the hand of the civil magistrate, the case being known and proved, or else by the hand of God being known by mortality or the pestilence, as the Targum of Jonathan, or they should die childless; See Gill on Lev 20:17.

Sanctify yourselves therefore, and be ye holy--The minute specification of the incestuous and unnatural crimes here enumerated shows their sad prevalence amongst the idolatrous nations around, and the extreme proneness of the Israelites to follow the customs of their neighbors. It is to be understood, that, whenever mention is made that the offender was "to be put to death" without describing the mode, stoning is meant. The only instance of another form of capital punishment occurs in Lev 20:14, that of being burnt with fire; and yet it is probable that even here death was first inflicted by stoning, and the body of the criminal afterwards consumed by fire (Jos 7:15).