TT #171 · Parashas Shoftim · Fourth Aliyah · Passuk 18:10
There shall not be found among you one who passes his son or his daughter through the fire, a diviner of divinations, a soothsayer, a diviner by omens, or a sorcerer.
Torah Temimah points to Sanhedrin 64a–65a / Sifrei.
TT lemma: מַעֲבִיר בְּנוֹ וּבִתּוֹ בָּאֵשׁ.
Sefaria — Sanhedrin 64a–65a / Sifrei
English: ‘One who passes his son or his daughter through the fire’ – this is Molech.
Derash identifying the practice (Bavli / Sifrei) — the verse is the source for the prohibition of Molech worship.
Passing a child through fire is identified with the worship of Molech and is absolutely forbidden.