Albert Barnes Commentary 1 Kings 16:17

"And Omri went up from Gibbethon, and all Israel with him, and they besieged Tirzah." — 1 Kings 16:17 (ASV)

Went up - The expression “went up” accurately marks the army’s ascent from the Shephelah, where Gibbethon was situated (Joshua 19:44), to the hill country of Israel, on the edge of which Tirzah stood (1 Kings 14:17).