Rashi on Leviticus 20:3/רש"י על ויקרא כ׳:ג׳

1אתן את פני ‎ is taken in the sense of, פנאי שלי, My leisure — I shall turn away from everything else that I am occupied with, and will busy Myself with him alone (Sifra, Kedoshim, Section 4 13; cf. Rashi on Leviticus 17:10).

2באיש AGAINST THAT MAN — but not against the whole congregation if they thus sin (Sifra, Kedoshim, Section 4 13), for the community as a whole is never punished with excision.

3כי מזרעו נתן למלך BECAUSE HE HATH GIVEN OF HIS SEED TO THE MOLECH — These words appear to be redundant since in v. 20 the nature of the sin is already mentioned, but because Scripture states (Deuteronomy 18:10) “[There shall not be found among you] any one that maketh his son or his daughter pass through the fire", one might think that this law applies only to ones children; whence do we know that it applies also to one’s son's son and one's daughter’s son? Because Scripture states here, “because he hath given of his offspring to the Molech". Whence do we know that illegitimate offspring are also included in this law? Because Scripture states again (v. 4) “when he giveth of his seed to the Molech” — whether legitimate or not (Sifra, Kedoshim, Section 4 6-7; Sanhedrin 64b).

4למען טמא את מקדשי TO DEFILE MY מקדש — This means the “Congregation of Israel" which is sanctified to Me. The word מקדש does not imply the Sanctuary only but anything that is holy to God, as in the expression (Leviticus 21:23) “that he profane not my holy things (‎‎‏מקדשי‎).