Heart Desires

1 Kings 11:37
However, as for you, I will take you, and you will rule over all that your heart desires; you will be king over Israel.

This promise is for Jeroboam, who would soon rule over 10 of the 12 tribes. Only Judah remained to Solomon's descendants, for David's sake, and for the sake of the King to come.
I find it a little unusual that God spoke of heart's desires in this context. The promise was followed by the usual condition: if Jeroboam walked in God's ways and kept God's commands, he would have a lasting dynasty, just like David's, though no one and no tribe would ever take David's exact place.
The whole phrase, rule over all that your heart desires, seemed familiar, and it did occur in 2 Samuel 3:21. But it wasn't God talking. Abner was acting as power broker when he got mad at Saul and offered to help David.
Seeing the end, God must have known that Jeroboam wouldn't last long. But he did what God needed him to, and for that God offered him a shot at his heart's desires.