A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
4 Kings (2 Kings) 12:2
kg2 12:2JEHOASH REIGNS WELL WHILE JEHOIADA LIVED. (2Ki. 12:1-18)
Jehoash did that which was right in the sight of the Lord--so far as related to his outward actions and the policy of his government. But it is evident from the sequel of his history that the rectitude of his administration was owing more to the salutary influence of his preserver and tutor, Jehoiada, than to the honest and sincere dictates of his own mind.
4 Kings (2 Kings) 12:3
kg2 12:3But the high places were not taken away--The popular fondness for the private and disorderly rites performed in the groves and recesses of hills was so inveterate that even the most powerful monarchs had been unable to accomplish their suppression; no wonder that in the early reign of a young king, and after the gross irregularities that had been allowed during the maladministration of Athaliah, the difficulty of putting an end to the superstitions associated with "the high places" was greatly increased.
4 Kings (2 Kings) 12:4
kg2 12:4Jehoash said to the priests, &c.--There is here given an account of the measures which the young king took for repairing the temple by the levying of taxes: 1. "The money of every one that passeth the account," namely, half a shekel, as "an offering to the Lord" (Exo 30:13). 2. "The money that every man is set at," that is, the redemption price of every one who had devoted himself or any thing belonging to him to the Lord, and the amount of which was estimated according to certain rules (Lev 27:1-8). 3. Free will or voluntary offerings made to the sanctuary. The first two were paid annually (see Ch2 24:5).
4 Kings (2 Kings) 12:7
kg2 12:7Why repair ye not the breaches of the house?--This mode of collection not proving so productive as was expected (the dilatoriness of the priests was the chief cause of the failure), a new arrangement was proposed. A chest was placed by the high priest at the entrance into the temple, into which the money given by the people for the repairs of the temple was to be put by the Levites who kept the door. The object of this chest was to make a separation between the money to be raised for the building from the other moneys destined for the general use of the priests, in the hope that the people would be more liberal in their contributions when it was known that their offerings would be devoted to the special purpose of making the necessary repairs. The duty of attending to this work was no longer to devolve on the priests, but to be undertaken by the king.
4 Kings (2 Kings) 12:11
kg2 12:11they gave the money, being told, into the hands of them that did the work--The king sent his secretary along with an agent of the high priest to count the money in the chest from time to time (Ch2 24:11), and deliver the amount to the overseers of the building, who paid the workmen and purchased all necessary materials. The custom of putting sums of certain amount in bags, which are labelled and sealed by a proper officer, is a common way of using the currency in Turkey and other Eastern countries.
4 Kings (2 Kings) 12:13
kg2 12:13Howbeit there were not made . . . bowls, &c.--When the repairs of the temple had been completed, the surplus was appropriated to the purchase of the temple furniture. The integrity of the overseers of the work being undoubted, no account was exacted of the way in which they applied the money given to them, while other moneys levied at the temple were left to the disposal of the priests as the law directed (Lev 5:16; Num 5:8).
4 Kings (2 Kings) 12:17
kg2 12:17Then Hazael . . . fought against Gath--(See on Ch2 24:23).
4 Kings (2 Kings) 12:20
kg2 12:20HE IS SLAIN. (Kg2 12:19-21)
his servants arose . . . and slew Joash in the house of Millo--(See on Ch2 24:25).