And his servants arose, and made a conspiracy, and {k} slew Joash in the house of {l} Millo, which goeth down to Silla.

(k) Because he had put Zachariah the son of Jehoiada to death, 2Ch 24:25.

(l) Read 2Sa 5:9.

Wesley's Notes

12:20 And slew Joash - We are told, in the Chronicles, that his murdering the prophet, Jehoiada's son, was the provocation. In this, how unrighteous so ever they were, yet the Lord was righteous. And this was not the only time, that he let even kings know, it was at their peril, if they touched his anointed, or did his prophets any harm. Thus fell Joash, who began in the spirit, and ended in the flesh. And indeed God usually sets marks of his displeasure upon apostates, even in this life.

King James Translators' Notes

the house...: or, Bethmillo

Jamieson-Fausset-Brown Bible Commentary

20. his servants arose . and slew Joash in the house of Millo-(See on [339]2Ch 24:25).

Matthew Henry's Concise Commentary

12:17-21 Let us review the character of Jehoash, and consider what we may learn from it. When we see what a sad conclusion there was to so promising a beginning, it ought to make us seek into our spiritual declinings. If we know any thing of Christ as the foundation of our faith and hope, let us desire to know nothing but Christ. May the work of the blessed Spirit on our souls be manifest; may we see, feel, and be earnest, in seeking after Jesus in all his fulness, suitableness, and grace, that our souls may be brought over from dead works to serve the living and true God.