1 Kings 16:14-17
English Standard Version
15In the twenty-seventh year of Asa king of Judah, Zimri reigned seven days in Tirzah. Now the troops were encamped against Gibbethon, which belonged to the Philistines,
16and the troops who were encamped heard it said, "Zimri has conspired, and he has killed the king." Therefore all Israel made Omri, the commander of the army, king over Israel that day in the camp.
17So Omri went up from Gibbethon, and all Israel with him, and they besieged Tirzah.