For he built up again. — The LXX. and Vulg. imitate the Hebrew idiom, and he returned and built — i.e., and he rebuilt.
The high places... altars for Baal... a grove (an Ashçrah). — “The idols, the sun-pillars, the ashçrim, the sacred trees, and all the other pagan or half-pagan symbols, so plainly inconsistent with the prophetic faith, were of the very substance of Israel’s worship in the popular sanctuaries” (Prof. Robertson Smith).
As did Ahab. — See 1 Kings 16:32-33.
Worshipped all the host of heaven. — See Notes on 2 Kings 17:16, and comp. 2 Kings 23:12. The Babylonian star-worship and astrology, with concomitant superstitions, had been introduced under Ahaz.