Komentarz do Powtórzonego Prawa 18:10

מעביר בנו ובתו באש [THERE SHALL NOT BE FOUND AMONG YOU ANYONE] THAT MAKETH HIS SON OR HIS DAUGHTER TO PASS THROUGH THE FIRE — This was the way of worshipping Molech. They made two pyres, one on this side and one on the other (one opposite the other) and passed it (the child) between them (cf. Sanhedrin 64b).

לא ימצא בך, even among non-Jewish residents of the Holy Land. A prominent example would be the woman used by King Sha-ul to produce the deceased prophet Samuel to give him a message. (Samuel I 28)

לא ימצא בך מעביר בנו ובתו באש, קוסם קסמים, מעונן, נחש, ומכשף וחובר חבר, ושואל אוב וידעוני, ודורש אל המתים. “There shall not be found among you one who causes his son or daughter to pass through the fire; one who practices divinations, an astrologer, one who reads omens, a sorcerer. Or, an animal charmer, one who inquires of Ov or Yidoni, or one who consults the dead.” These two verses enumerate nine different varieties of תועבות, abominable practices which the Canaanites were in the habit of relying on.
The Torah lists the practice the Moloch cult first, which involved exposing one’s children to the fire in order to assuage that deity’s feelings. There is no more despicable form of idolatry than to sacrifice one’s own flesh and blood to such cults. Seeing that this practice is so distasteful to G’d, anyone who is guilty of it is subject to the karet penalty (compare Leviticus 20,3). People who violate Torah law by committing any of the other abominations listed here only qualify for 39 lashes, i.e. corporal punishment. After the Torah concluded by warning us not to become guilty of such practices, the Torah continues by emphasising the positive, i.e. asking us תמים תהיה עם ה' אלו-היך, “you shall be wholehearted with the Lord your G’d” (verse 13).
The expression מעביר used by the Torah describing the Moloch cult, means that the father makes the child walk between two columns of fire; I explained this already in connection with Leviticus 18,21.