1 Kings 2:22-26

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.

Then to Abiathar the priest the king said, “Go to Anathoth to your own field, for you deserve to die; but I will not put you to death at this time, because you carried the ark of the Lord God before my father David, and because you were afflicted in everything with which my father was afflicted.”