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. (2 Kings 23:4)
To a place regarded as already cursed and unclean, so that the soil of Judah itself might not be further defiled.
Kidron.
The Kidron was the valley running north and south to the east of Jerusalem between the city and the Mt. of Olives. The fields of Kidron were probably the northern part of this valley where the ravine expands considerably (see Jer. 31:40). Asa had burned the idol of Maachah by the brook Kidron (1 Kings 15:13).
It seems that the purging in the 12th year of Josiah’s reign (2 Chron. 34:3) was only a partial work. The presence of the vessels made for the service of Baal, for Asherah, and for the heavenly host, in the sacred Temple, indicates the extent to which idolatry had taken hold of the people of Judah. The nation had almost completely alienated themselves from God and reverted to the ways of the heathen they had dispossessed. Josiah determined to exterminate the last vestige of idolatry from the land.
The second order.
Three distinct orders in the priestly and Levitical organization are here referred to (see ch. 25:18).
All the vessels.
This would include not only vessels in the strictest sense of the term but the whole apparatus of worship, including utensils, images, altars, etc.