Matthew Henry Commentary 1 Kings 2:12-25

"And Solomon sat upon the throne of David his father; and his kingdom was established greatly. Then Adonijah the son of Haggith came to Bath-sheba the mother of Solomon. And she said, Comest thou peaceably? And he said, Peaceably. He said moreover, I have somewhat to say unto thee. And she said, Say on. And he said, Thou knowest that the kingdom was mine, and that all Israel set their faces on me, that I should reign: howbeit the kingdom is turned about, and is become my brother`s; for it was his from Jehovah. And now I ask one petition of thee; deny me not. And she said unto him, Say on. And he said, Speak, I pray thee, unto Solomon the king (for he will not say thee nay), that he give me Abishag the Shunammite to wife. And Bath-sheba said, Well; I will speak for thee unto the king. Bath-sheba 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 throne to be set for the king`s mother; and she sat on his right hand. Then she said, I ask one small petition of thee; deny me not. And the king said unto her, Ask on, my mother; for I will not deny thee. And she said, Let Abishag the Shunammite be given to Adonijah thy brother to wife. And 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. Then king Solomon sware by Jehovah, saying, God do so to me, and more also, if Adonijah hath not spoken this word against his own life. Now therefore as Jehovah liveth, who hath established me, and set me on the throne of David my father, and who hath made me a house, as he promised, surely Adonijah shall be put to death this day. And king Solomon sent by Benaiah the son of Jehoiada; and he fell upon him, so that he died." — 1 Kings 2:12-25 (ASV)

Solomon received Bathsheba with all the respect that was owing to a mother; but let no one be asked for what they ought not to grant. It ill becomes a good man to present a bad request, or to involve himself 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 have lost their heads by grasping at a crown.