1 Kings 16:15-17

15In the twenty-seventh year of Asa’s reign over Judah, Zimri became king over Israel; he ruled for seven days in Tirzah. Zimri’s revolt took place while the army was deployed in Gibbethon, which was in Philistine territory.

16While deployed there, the army received this report: “Zimri has conspired against the king and assassinated him.” So all Israel made Omri, the commander of the army, king over Israel that very day in the camp.

17Omri and all Israel went up from Gibbethon and besieged Tirzah.