2 Kings 3:7

And he went and sent to Jehoshaphat the king of Judah, saying,
the king of Moab hath rebelled against me
By refusing to pay him tribute:

wilt thou go up with me against Moab to battle? and he said, I will go
up;
which he agreed to, partly to encourage in the reformation of religion which he had begun, and partly to chastise the Moabites for their invasion of his country, ( 2 Chronicles 20:1 ) .

I am as thou art, my people as thy people, and my horses as thy horses;
the same answer he returned to Ahab, (See Gill on 1 Kings 22:4).