Calvin's Commentaries, Vol. 5: Harmony of the Law, Part III, tr. by John King, [1847-50], at sacred-texts.com
20. Moreover, thou shalt not lie carnally with thy neighbor’s wife, to defile thyself with her.
20. Uxori proximi tui non dabis concubitum tuum in semine, ut polluaris cum ea.
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. Wherefore, God has justly enumerated this crime amongst the abominations of the Gentiles, as may be more clearly seen from the exordium of the chapter from whence this passage is taken.