Charles Ellicott Commentary 1 Kings 1:11

"Then Nathan spake unto Bath-sheba the mother of Solomon, saying, Hast thou not heard that Adonijah the son of Haggith doth reign, and David our lord knoweth it not?" — 1 Kings 1:11 (ASV)

Therefore Nathan.—The initiative taken by Nathan is especially natural, since he had been the medium both of the prophecy to David of the son who should build the Lord’s house (2 Samuel 7:12–15), and also of the blessing on Solomon, embodied in the name Jedidiah (“beloved of Jehovah,” 2 Samuel 12:25). Perhaps for this very reason the conspirators had altogether kept their distance from him.