1 Kings 20:1 - Joseph Benson’s Commentary on the Old and New Testaments

Gathered all his host To war against Israel: wherein his design was to enlarge the conquest which his father had made; but God's design was to punish Israel for their apostacy and idolatry. There were thirty and two kings with him Petty kings, such as were in Canaan in Joshua's time, who indeed were no more than governors of cities or small territories: these were either subject or tributary to Ben-hadad, or hired by him. He were up and besieged Samaria He did not actually besiege it; for his army was routed before he could do it. But the sense is, He went up in order to besiege it.