Read 2 Chronicles 24:22 Using Other Translations
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.
Thus Joash the king did not remember the kindness that Jehoiada, Zechariah's father, had shown him, but killed his son. And when he was dying, he said, "May the LORD see and avenge!"
That was how King Joash repaid Jehoiada for his loyalty—by killing his son. Zechariah’s last words as he died were, “May the LORD see what they are doing and avenge my death!”