priests of the second order (or degree), i.e. ordinary priests.
the grove. the 'Asherah. See App-42.
host of heaven. Compare 2 Kings 21:3.
burned them. As prescribed in Deuteronomy 7:25.
unto Beth-el. To defile the altar there, according to the prophecy in 1 Kings 13:2.
4 And the king commanded Hilkiah the high priest, and the priests of the second order, and the keepers of the door, to bring forth out of the temple of the LORD all the vessels that were made for Baal, and for the grove, and for all the host of heaven: and he burned them without Jerusalem in the fields of Kidron, and carried the ashes of them unto Bethel.