2 Kings 9:5-7 (KJV)

5 And when he came, (speaking of the young prophet who was sent by Elisha) 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. 6 And he arose, and went into the house; and (the young prophet) poured the oil on (Jehu’s) 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. 7 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.