1 Kings 1:13

Didst not thou... swear. — Of this oath we have no mention elsewhere. It may have belonged to the time of Solomon’s birth (2 Samuel 12:24). In 1 Chronicles 22:6, we find a designation of Solomon for succession, apparently earlier than this time — it being clearly understood (see 1 Kings 1:20), according to Oriental custom, that such designation, without strict regard to priority of birth, lay in the prerogative of the reigning king.