1 Samuel 16:12-13

So Jesse sent and had his youngest son brought in. He was a fine boy, tanned, and handsome. The LORD said to Samuel, “Go, appoint him, because he is the one.” So Samuel took the container of olive oil and poured it on Jesse’s youngest son to appoint him in front of his brothers. From that day on, the LORD’s Spirit worked in David. Samuel then went back to Ramah.