1 Samuel 16:5-15

5 "Greetings," he replied, "I have come to sacrifice to the LORD. Perform the ceremonies to make yourselves holy, and come with me to the sacrifice." He performed the ceremonies for Jesse and his sons and invited them to the sacrifice.
6 When they came, he saw Eliab and thought, "Certainly, here in the LORD's presence is his anointed king."
7 But the LORD told Samuel, "Don't look at his appearance or how tall he is, because I have rejected him. God does not see as humans see. Humans look at outward appearances, but the LORD looks into the heart."
8 Then Jesse called Abinadab and brought him to Samuel. But Samuel said, "The LORD has not chosen this one either."
9 Then Jesse had Shammah come to Samuel. "The LORD has not chosen this one either," Samuel said.
10 So Jesse brought seven [more] of his sons to Samuel, but Samuel told Jesse, "The LORD has not chosen [any of] these.
11 Are these all the sons you have?" "There's still the youngest one," Jesse answered. "He's tending the sheep." Samuel told Jesse, "Send someone to get him. We won't continue until he gets here."
12 So Jesse sent for him. He had a healthy complexion, attractive eyes, and a handsome appearance. The LORD said, "Go ahead, anoint him. He is the one."
13 Samuel took the flask of olive oil and anointed David in the presence of his brothers. The LORD's Spirit came over David and stayed with him from that day on. Then Samuel left for Ramah.
14 Now, the LORD's Spirit had left Saul, and an evil spirit from the LORD tormented him.
15 Saul's officials told him, "An evil spirit from God is tormenting you.