Thus Joash the king remembered not the kindness which Jehoiada his father had done to him, but slew his son. And when he died, he said, The LORD look upon it, and require it. The Lord look upon it, and require it - And so he did; for, at the end of that year, the Syrians came against Judah, destroyed all the princes of the people, sent their spoils to Damascus; and Joash, the murderer of the prophet, the son of his benefactor, was himself murdered by his own servants. Here was a most signal display of the Divine retribution.
On the subject of the death of this prophet the reader is requested to refer to the note on Matthew 23:34, Matthew 23:35.