Charles Ellicott Commentary 1 Kings 2:23

"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." — 1 Kings 2:23 (ASV)

God do so to me, and more also.—See Ruth 1:17; 1 Samuel 3:17; 1 Samuel 14:44; 1 Samuel 20:13; 1 Samuel 25:22; 2 Samuel 11:14; and other similar passages. This well-known formula of imprecation—which the Septuagint renders, “May God do these things to me and add these things also”—was probably accompanied with some gesture signifying utter destruction.