19 Yet he sent prophets among them to bring them back to the Lord; they testified against them, but they would not listen. 20 Then the spirit of God took possession of Zechariah son of the priest Jehoiada; he stood above the people and said to them, "Thus says God: Why do you transgress the commandments of the Lord, so that you cannot prosper? Because you have forsaken the Lord, he has also forsaken you." 21 But they conspired against him, and by command of the king they stoned him to death in the court of the house of the Lord. 22 King Joash did not remember the kindness that Jehoiada, Zechariah's father, had shown him, but killed his son. As he was dying, he said, "May the Lord see and avenge!"
Matthew Henry's Commentary on 2 Chronicles 24:19-22
Commentary on 2 Chronicles 24:15-27
(Read 2 Chronicles 24:15-27)
See what a great judgment on any prince or people, the death of godly, zealous, useful men is. See how necessary it is that we act in religion from inward principle. Then the loss of a parent, a minister, or a friend, will not be losing our religion. Often both princes and inferior people have been flattered to their ruin. True grace alone will enable a man to bring forth fruit unto the end. Zechariah, the son of Jehoiada, being filled with the Spirit of prophecy, stood up, and told the people of their sin. This is the work of ministers, by the word of God, as a lamp and a light, to discover the sin of men, and expound the providences of God. They stoned Zechariah to death in the court of the house of the Lord. Observe the dying martyr's words: The Lord look upon it, and require it! This came not from a spirit of revenge, but a spirit of prophecy. God smote Joash with great diseases, of body, or mind, or both, before the Syrians departed from him. If vengeance pursue men, the end of one trouble will be but the beginning of another. His own servants slew him. These judgments are called the burdens laid upon him, for the wrath of God is a heavy burden, too heavy for any man to bear. May God help us to take warning, to be upright in heart, and to persevere in his ways to the end.