John Gill Commentary 1 Kings 22:4

"And he said unto Jehoshaphat, Wilt thou go with me to battle to Ramoth-gilead? And Jehoshaphat said to the king of Israel, I am as thou art, my people as thy people, my horses as thy horses." — 1 Kings 22:4 (ASV)

Ver. 4 And he said to Jehoshaphat, will you go with me to battle to Ramothgilead ? this affair being lately canvassed at the council board, and very much on Ahab's mind, he puts this question to Jehoshaphat, his visitor, relation, and ally; wisely considering that his own forces were small, and that to have such an auxiliary might be of great advantage to him:

and Jehoshaphat said to the king of Israel, I am as you are, my people as your people, my horses as your horses ; meaning, that he and his soldiers, foot and horse, were at his service.