What does 1 Samuel 15:28 mean?

After hearing that the Lord had rejected him as king over Israel, Saul finally confessed that he had sinned in disobeying God's command (1 Samuel 15:24). He begged Samuel to pardon him and return to bow before the Lord, but the prophet had simply restated that the Lord had rejected Saul as king (1 Samuel 15:26). In a moment of desperation, Saul grabbed the edge of Samuel's robe as he was turning to leave. Holding the hem of a robe in this way symbolized showing submission to a superior. Saul, though, apparently grabbed at the robe with too much force and tore it (1 Samuel 15:27).

Samuel uses this as a symbolic illustration: the Lord has torn away the kingdom from Saul and has given it to someone else. Samuel identifies this other man only as a "neighbor" and someone who his better than Saul (cf. 1 Samuel 13:13–14). The fulfillment of this promise, David, will be introduced in the next chapter (1 Samuel 16).

Samuel uses the phrase "this day" to declare exactly when the kingdom was removed, in God's view, from Saul and given to David by the Lord. While the spiritual connection is severed, an earthly transfer of power will not take place for some time.