But. — And.
When. — So some MSS. The ordinary text has, “about the time of Ahab’s death” (ke for be).
Rebelled — i.e., refused payment of the annual tribute.
Related Commentaries of 2 Kings 3:5
2 Kings 3:5
5 But it came to pass, when Ahab was dead, that the king of Moab rebelled against the king of Israel.