Leviticus 20:2-3

2Thou shalt say also to the children of Israel, Every one of the children of Israel, or of the strangers who sojourn in Israel, that giveth of his seed unto Molech, shall certainly be put to death: the people of the land shall stone him with stones.

3And I will set my face against that man, and will cut him off from among his people; because he hath given of his seed unto Molech, so as to make my sanctuary unclean, and to profane my holy name.