You must not lie carnally with your neighbor’s wife and thus defile yourself with her.
The object of this passage is the same as that of the foregoing ones. For, whilst all fornication pollutes a man, there is grosser impurity in adultery, because the sanctity of marriage is violated, and by the commingling of seed a spurious and illegitimate offspring is derived.
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.
Commenting on Leviticus 18:19-30
Moreover, thou shalt not lie carnally with thy neighbour's wife,.... Which is adultery, and a breach of the seventh command, Exo 20:14, to defile thyself with her; not only adultery is a defiling a man's wife, as it is sometimes called, but the adulterer defiles himself: all sin is of a defiling nature, but especially this, which defiles a man both in soul and body...