The altars that were on the top of the upper chamber— Or, The altars on the house-top. The ancient idolaters and the magi were wont to sacrifice not only upon high places and mountains, but also upon the housetops. See Jeremiah 32:29.
Related Commentaries of 2 Kings 23:12
2 Kings 23:12
12 And the altars that were on the top of the upper chamber of Ahaz, which the kings of Judah had made, and the altars which Manasseh had made in the two courts of the house of the LORD, did the king beat down, and brake them downc from thence, and cast the dust of them into the brook Kidron.