Albert Barnes 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)

The son of Haggith - Compare the marginal reference. This expression was well chosen to touch the pride of Bathsheba: “Adonijah; not your son, but the son of your rival, Haggith.”