Albert Barnes Commentary 1 Kings 22:14

"And Micaiah said, As Jehovah liveth, what Jehovah saith unto me, that will I speak." — 1 Kings 22:14 (ASV)

Micaiah, as a true prophet of Yahweh, of course rejected the counsel offered to him, which he felt to be at once wicked and foolish. Compare this also to the resolution of Balaam.