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
2 Chronicles 31:1
ch2 31:1THE PEOPLE FORWARD IN DESTROYING IDOLATRY. (Ch2 31:1-10)
all Israel . . . present went out to the cities of Judah--The solemnities of this paschal season left a deep and salutary impression on the minds of the assembled worshippers; attachment to the ancient institutions of their country was extensively revived; ardor in the service of God animated every bosom; and under the impulse of the devout feelings inspired by the occasion, they took measures at the close of the passover for extirpating idolatrous statues and altars out of every city, as at the beginning of the festival they had done in Jerusalem.
Judah and Benjamin--denote the southern kingdom.
Ephraim also and Manasseh--refer to the northern kingdom. This unsparing demolition of the monuments of idolatry would receive all encouragement from the king and public authorities of the former; and the force of the popular movement was sufficient to effect the same results among the tribes of Israel, whatever opposition the power of Hoshea or the invectives of some profane brethren might have made. Thus the reign of idolatry being completely overthrown and the pure worship of God re-established throughout the land, the people returned every one to his own home, in the confident expectation that, through the divine blessing, they would enjoy a happy future of national peace and prosperity.
2 Chronicles 31:2
ch2 31:2Hezekiah appointed the courses of the priests, &c.--The king now turned his attention to provide for the orderly performance of the temple-worship--arranging the priests and Levites in their courses, assigning to every one his proper place and functions--and issuing edicts for the regular payment of those dues from which the revenues of the sanctuary were derived. To set a proper example to his subjects, his own proportion was announced in the first instance, for to the king it belonged, out of his privy purse, to defray the expenses of the altar, both stated and occasional (Num 28:3-4, Num 28:9, Num 28:11, Num 28:19); and in making this contribution from his own means, Hezekiah followed the course which David and Solomon had taken before him (see Ch2 8:14; Kg1 9:25). Afterwards he reappointed the people's dues to the temple; and from its being necessary to issue a royal mandate in reference to this matter, it appears that the sacred tribute had been either totally neglected, or (as the idolatrous princes were known to appropriate it to their own purposes) the people had in many cases refused or evaded the duty. But with the improved state of public feeling, Hezekiah's commandment was readily obeyed, and contributions of first-fruits and tithes were poured in with great liberality from all parts of Judah, as well as from Israel. The first-fruits, even of some articles of produce that were unfit for sacrifice (Lev 2:11), such as honey (Margin, "dates"), were appropriated to the priests (Num 18:12-13; Deu 18:4). The tithes (Lev 27:31) were intended for the support of the whole Levitical tribe (Num 18:8, Num 18:20, Num 18:24).
2 Chronicles 31:6
ch2 31:6and laid them by heaps--The contributions began to be sent in shortly after the celebration of the passover, which had taken place in the middle of the second month. Some time would elapse before the king's order reached all parts of the kingdom. The wheat harvest occurred in the third month, so that the sheaves of that grain, being presented before any other, formed "the foundation," an under-layer in the corn stores of the temple. The first-fruits of their land produce which were successively sent in all the summer till the close of the fruit and vintage season, that is, the seventh month, continued to raise heap upon heap.
2 Chronicles 31:9
ch2 31:9Hezekiah questioned with the priests and the Levites concerning the heaps--The object of his enquiries was to ascertain whether the supplies afforded the prospect of a sufficient maintenance for the members of the sacred order.
2 Chronicles 31:10
ch2 31:10Azariah . . . answered . . . we have had enough--This is probably the person mentioned (Ch2 26:17), and his reply was to the following purport: There has been an abundant harvest, and a corresponding plenty in the incoming of first-fruits and tithes; the people have testified their gratitude to Him who has crowned the year with His goodness by their liberality towards His servants.
2 Chronicles 31:11
ch2 31:11HEZEKIAH APPOINTS OFFICERS TO DISPOSE OF THE TITHES. (Ch2 31:11-19)
Hezekiah commanded to prepare chambers in the house of the Lord--storehouses, granaries, or cellars; either the old ones, which had been allowed through neglect to fall into decay, were to be repaired, or additional ones built. Private individuals brought their own first-fruits to the temple; but the tithes were levied by the Levites, who kept a faithful account of them in their several places of abode and transmitted the allotted proportion to the priests. Officers were appointed to distribute equal rations to all in the cities of the priests who, from age or other reasons, could not repair to the temple. With the exception of children under three years of age--an exception made probably from their being considered too young to receive solid food--lists were kept of the number and age of every male; of priests according to their fathers' house, and Levites from twenty years (see Num 4:3; Num 28:24; Ch1 23:24). But, besides, provision was also made for their wives, daughters, and servants.
2 Chronicles 31:18
ch2 31:18for in their set office they sanctified themselves--This is the reason assigned for providing for the wives and children out of the revenues of the sanctuary, that priests, withdrawing from those secular pursuits by which they might have maintained their households, devoted themselves entirely to the functions of the ministry.
2 Chronicles 31:20
ch2 31:20HIS SINCERITY OF HEART. (Ch2 31:20-21)
Hezekiah . . . wrought that which was good and right--He displayed the qualities of a constitutional king, in restoring and upholding the ancient institutions of the kingdom; while his zealous and persevering efforts to promote the cause of true religion and the best interests of his subjects entitled him to be ranked with the most illustrious of his predecessors (Kg2 18:15).