Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Lev 20:1-9) Law against sacrificing children to Moloch, Of children that curse their parents.
(v. 10-27) Laws repeated, Holiness enjoined.
Are we shocked at the unnatural cruelty of the ancient idolaters in sacrificing their children? We may justly be so. But are there not very many parents, who, by bad teaching and wicked examples, and by the mysteries of iniquity which they show their children, devote them to the service of Satan, and forward their everlasting ruin, in a manner even more to be lamented? What an account must such parents render to God, and what a meeting will they have with their children at the day of judgment! On the other hand, let children remember that he who cursed father or mother was surely put to death. This law Christ confirmed. Laws which were made before are repeated, and penalties annexed to them. If men will not avoid evil practices, because the law has made these practices sin, and it is right that we go on that principle, surely they should avoid them when the law has made them death, from a principle of self-preservation. In the midst of these laws comes in a general charge, Sanctify yourselves, and be ye holy. It is the Lord that sanctifies, and his work will be done, though it be difficult. Yet his grace is so far from doing away our endeavours, that it strongly encourages them. Work out your salvation, for it is God that worketh in you.
These verses repeat what had been said before, but it was needful there should be line upon line. What praises we owe to God that he has taught the evil of sin, and the sure way of deliverance from it! May we have grace to adorn the doctrine of God our Saviour in all things; may we have no fellowship with unfruitful works of darkness, but reprove them.