The Lord asked Samuel, “How long are you going to mourn for Saul now that I have rejected him as king of Israel? Fill a flask with olive oil and go. I’m sending you to Jesse in Bethlehem because I’ve selected one of his sons to be king.”
He even took off his clothes as he prophesied in front of Samuel and lay there naked all day and all night. This is where the saying, “Is Saul one of the prophets?” came from.