2 He had brothers, the sons of Jehosh'aphat: Azari'ah, Jehi'el, Zechari'ah, Azari'ah, Michael, and Shephati'ah; all these were the sons of Jehosh'aphat king of Judah. 3 Their father gave them great gifts, of silver, gold, and valuable possessions, together with fortified cities in Judah; but he gave the kingdom to Jeho'ram, because he was the first-born. 4 When Jeho'ram had ascended the throne of his father and was established, he slew all his brothers with the sword, and also some of the princes of Israel.
Matthew Henry's Commentary on 2 Chronicles 21:2-4
Commentary on 2 Chronicles 21:1-11
(Read 2 Chronicles 21:1-11)
Jehoram hated his brethren, and slew them, for the same reason that Cain hated Abel, and slew him, because their piety condemned his impiety. In the mystery of Providence such men sometimes prosper for a time; but the Lord has righteous purposes in permitting such events, part of which may now be made out, and the rest will be seen hereafter.