John Calvin Reformed @genevareformer

18:21. Thou shalt not let any of thy seed. In these three precepts Moses more lightly touches on what we have lately seen set forth at greater length in Deuteronomy; for there he condemns impious offerings, as well as the responses of familiar spirits, magical arts, and enchantments.

Matthew Henry Presbyterian @wholebiblehenry

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

John Gill Reformed Baptist @doctorgill

And thou shalt not let any of thy seed pass through the fire to Molech,.... The name of an image or idol, according to Aben Ezra, who observes, that their wise men interpret it as a general name for everyone whom they made to reign over them; and it is right, he says, that it is the abomination of the children of Ammon, and so...