2 Kings 10:24-25

24Then they went in to offer sacrifices and burnt offerings. Now Jehu had stationed eighty men outside and said, "The man who allows any of those whom I give into your hands to escape shall forfeit his life."

25So as soon as he had made an end of offering the burnt offering, Jehu said to the guard and to the officers, "Go in and strike them down; let not a man escape." So when they put them to the sword, the guard and the officers cast them out and went into the inner room of the house of Baal,