1 Kings 2:23-25

23Then King Solomon took an oath by the Lord: “May God punish me and do so severely if Adonijah has not made this request at the cost of his life.

24And now, as the Lord lives — the one who established me, seated me on the throne of my father David, and made me a dynasty as he promised  — I swear Adonijah will be put to death today!”

25Then King Solomon dispatched Benaiah son of Jehoiada, who struck down Adonijah, and he died.