1 Kings 2:20-22
2:20 She said, “I would like to ask you for just one small favor. Please don’t refuse me.” He said, “Go ahead and ask, my mother, for I would not refuse you.”
2:21 She said, “Allow Abishag the Shunammite to be given to your brother Adonijah as a wife.”
2:22 King Solomon answered his mother, “Why just request Abishag the Shunammite for him? Since he is my older brother, you should also request the kingdom for him, for Abiathar the priest, and for Joab son of Zeruiah!”