John Gill Commentary 2 Kings 21:6

"And he made his son to pass through the fire, and practised augury, and used enchantments, and dealt with them that had familiar spirits, and with wizards: he wrought much evil in the sight of Jehovah, to provoke him to anger." — 2 Kings 21:6 (ASV)

And he made his son pass through the fire
To Molech, after the manner of the old Canaanites and Phoenicians; his son Amon, that succeeded him, and other children, as appears from (2 Chronicles 33:6) , where mention is made of the place where it was done, the valley of the son of Hinnom:

and observed times ;
lucky or unlucky, which was judged of by omens, and by the position of the stars:

and used enchantments, and dealt with familiar spirits and wizards ;
to get knowledge of things to come; all which are forbid and condemned by the law of Moses; see (Deuteronomy 18:10–12) ,

he wrought much wickedness in the sight of the Lord, to provoke him to
anger ;
in all those evils before mentioned, which were very abominable in the sight of God.