1 Samuel 16:1, 6-7, 12-13

Now the LORD said to Samuel, “You have mourned long enough for Saul. I have rejected him as king of Israel, so fill your flask with olive oil and go to Bethlehem. Find a man named Jesse who lives there, for I have selected one of his sons to be my king.”

When they arrived, Samuel took one look at Eliab and thought, “Surely this is the LORD’s anointed!” But the LORD said to Samuel, “Don’t judge by his appearance or height, for I have rejected him. The LORD doesn’t see things the way you see them. People judge by outward appearance, but the LORD looks at the heart.”

So Jesse sent for him. He was dark and handsome, with beautiful eyes. And the LORD said, “This is the one; anoint him.” So as David stood there among his brothers, Samuel took the flask of olive oil he had brought and anointed David with the oil. And the Spirit of the LORD came powerfully upon David from that day on. Then Samuel returned to Ramah.