God tells Samuel to anoint Saul
The day before Samuel met Saul, God told him to anoint Saul.
Key passages
1 Sa 9:15–16

Now Yahweh had revealed this to Samuel the day before Saul arrived, saying, “This time tomorrow I will send to you a man from the land of Benjamin, and you must anoint him as leader over my people Israel. He will deliver my people from the hand of the Philistines. For I have seen the suffering …

See also