21 She said, "Let Abishag the Shunammite be given to Adonijah your brother as his wife." 22 King Solomon answered his mother, "And why do you ask Abishag the Shunammite for Adonijah? Ask for him the kingdom also, for he is my older brother, and on his side are Abiathar[1] the priest and Joab the son of Zeruiah." 23 Then King Solomon swore by the Lord, saying, "God do so to me and more also if this word does not cost Adonijah his life! 24 Now therefore as the Lord lives, who has established me and placed me on the throne of David my father, and who has made me a house, as he promised, Adonijah shall be put to death today."
Matthew Henry's Commentary on 1 Kings 2:21-24
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.