21 She said, "Let Abishag the Shunammite be given to your brother Adonijah as his wife." 22 King Solomon answered his mother, "And why do you ask Abishag the Shunammite for Adonijah? Ask for him the kingdom as well! For he is my elder brother; ask not only for him but also for the priest Abiathar and for Joab son of Zeruiah!" 23 Then King Solomon swore by the Lord, "So may God do to me, and more also, for Adonijah has devised this scheme at the risk of his life! 24 Now therefore as the Lord lives, who has established me and placed me on the throne of my father David, and who has made me a house as he promised, today Adonijah shall be put to death." 25 So King Solomon sent Benaiah son of Jehoiada; he struck him down, and he died.
Matthew Henry's Commentary on 1 Kings 2:21-25
Commentary on 1 Kings 2:12-25
(Read 1 Kings 2:12-25)
Solomon received Bathsheba with all the respect that was owing to a mother; but let none be asked for that which they ought not to grant. It ill becomes a good man to prefer a bad request, or to appear in a bad cause. According to eastern customs it was plain that Adonijah sought to be king, by his asking for Abishag as his wife, and Solomon could not be safe while he lived. Ambitious, turbulent spirits commonly prepare death for themselves. Many a head has been lost by catching at a crown.