1 Kings 16:15-17

15In the twenty-seventh year of Asa king of Judah, Zimri reigned [over Israel] for seven days at Tirzah. Now the troops were camped against Gibbethon, [a city] which belonged to the Philistines,

16and the people who were camped heard it said, “Zimri has conspired and has also struck down the king.” So all Israel made Omri, the commander of the army, king over Israel that day in the camp.

17Then Omri went up from Gibbethon, and all Israel with him, and they besieged Tirzah.