1 Kings 2:21-25

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

But King Solomon answered and said to his mother, “And why are you requesting Abishag the Shunammite for Adonijah? Request for him the kingdom as well—since he is my older brother—for him, for Abiathar the priest, and for Joab the son of Zeruiah!”

Then King Solomon swore by the Lord, saying, “May God do so to me and more so, if Adonijah has not spoken this word against his own life!

Now then, as the Lord lives, who has established me and set me on the throne of David my father, and has made me a house just as He promised, Adonijah certainly shall be put to death today!”

Then King Solomon sent the order by Benaiah the son of Jehoiada; and he struck him so that he died.