1 Kings 2:21

19Bathsheba therefore went unto king Solomon, to speak unto him for Adonijah. And the king rose up to meet her, and bowed himself unto her, and sat down on his throne, and caused a seat to be set for the king’s mother; and she sat on his right hand.

20Then she said, I desire one small petition of thee; I pray thee, say me not nay. And the king said unto her, Ask on, my mother: for I will not say thee nay.

21And she said, Let Abishag the Shunammite be given to Adonijah thy brother to wife.

22And king Solomon answered and said unto his mother, And why dost thou ask Abishag the Shunammite for Adonijah? ask for him the kingdom also; for he is mine elder brother; even for him, and for Abiathar the priest, and for Joab the son of Zeruiah.

23Then king Solomon sware by the LORD, saying, God do so to me, and more also, if Adonijah have not spoken this word against his own life.