2 Kings 9:4-8

So the young man, even the young man the prophet, went to Ramoth-gilead.

And when he came, behold, the captains of the host were sitting; and he said, I have an errand to thee, O captain. And Jehu said, Unto which of all us? And he said, To thee, O captain.

And he arose, and went into the house; and he poured the oil on his head, and said unto him, Thus saith the LORD God of Israel, I have anointed thee king over the people of the LORD, even over Israel.

And thou shalt smite the house of Ahab thy master, that I may avenge the blood of my servants the prophets, and the blood of all the servants of the LORD, at the hand of Jezebel.

For the whole house of Ahab shall perish: and I will cut off from Ahab him that pisseth against the wall, and him that is shut up and left in Israel: