Charles Ellicott Commentary 2 Chronicles 17:6

"And his heart was lifted up in the ways of Jehovah: and furthermore he took away the high places and the Asherim out of Judah." — 2 Chronicles 17:6 (ASV)

And his heart was lifted up. — Gabhah lçbh, which usually, like the phrase of the Authorised version, has a bad meaning, as in 2 Chronicles 26:16. The margin is right here: “his courage rose high,” or “he grew bold” in the ways of Jehovah, that is, in the path of religious reform. Vulgate, “cum sumpsisset cor ejus audaciam propter vias Domini.”

Moreover. — And again, further. Referring to 2 Chronicles 17:3. Not only did he not seek the Baals, but more than this, he removed the high places, and so on. [This is the common explanation. But the sense may instead be: “And he again removed,” referring back to Asa’s reforms, 2 Chronicles 14:5.]

Groves. — Ashêrim, “Asherahs.” (2 Chronicles 14:3).