1 Kings 2:21-25

ISV(i) 21 So she asked him, “Give Abishag the Shunammite to your brother Adonijah as a wife.”
22 But King Solomon replied to his mother, “Why are you asking Abishag the Shunammite for Adonijah? Why not ask me to give up the kingdom for him, since he’s my older brother, and why not ask for Abiathar the priest, and for Zeruiah’s son Joab?”
23 Then King Solomon took this oath in the name of the LORD: “May God do so to me, and more besides, if Adonijah hasn’t endangered his life by bringing up this subject. 24 Now therefore, as the LORD lives, who has established me and set me on the throne of my father David, and who has established a dynasty, just like he promised, Adonijah will surely be executed today.” 25 So King Solomon sent for Jehoiada’s son Benaiah, who attacked and killed Adonijah.