1 Kings 2:21-25

21So she said, “Let Abishag the Shunammite be given to Adonijah your brother as wife.”

22King Solomon answered and said to his mother: “So why are you asking Abishag the Shunammite for Adonijah? Ask for him the kingdom as well—for he is my older brother—for him and for Abiathar the kohen, and for Joab son of Zeruiah!”

23Then King Solomon swore by Adonai saying: “May God do so to me and even more, if Adonijah does not pay with his own life for this request!

24Now therefore, as Adonai lives who has established me and set me on the throne of my father David, and who has made me a house as He promised, surely Adonijah shall be put to death this day.”

25Then King Solomon sent Benaiah son of Jehoiada. He struck him down and he died.