John Gill Commentary Leviticus 20:4

"And if the people at the land do at all hide their eyes from that man, when he giveth of his seed unto Molech, and put him not to death;" — Leviticus 20:4 (ASV)

And if the people of the land do any ways hide their eyes from
the man
That is, the people of the house of Israel, as the Targums of Onkelos and Jonathan; if the friends, relations, and neighbours of such a man, though they know what he is about to do, or has done, yet they shut their eyes wilfully, or look another way; or, however, wink and connive at his wickedness, and will not discover him, and bear witness against him; or if a court of judicature, before whom he comes, does not take the evidence of his crime, nor condemn for it, or are negligent in punishing him as the law directs, a gift having blinded their eyes, or they careless and remiss in their duty:

when he giveth his seed unto Molech ;
That is, a crime so heinous and abominable:

and kill him not ;
That is, do not bring witness against him, so as that he may be put to death, or do not upon the evidence given condemn him to death, or do not take care to have sentence executed, by stoning him to death.