Translations
He was utterly vile in his pursuit of idols, acting exactly as the Amorites had done — the very people Yahweh had driven out before the children of Israel.
He acted with utter abomination by going after idols, just as the Emori had done — whom YHWH drove out before the children of Isra'el.
And he did very abominably in following idols, according to all things as did the Amorites, whom the LORD cast out before the children of Israel.
He committed the most detestable acts by going after idols, just like the Amorites whom the LORD had driven out before the Israelites.)

