1 Samuel 16:1, 6-7, 10-13

And Jehovah said unto Samuel, How long wilt thou mourn for Saul, seeing I have rejected him from being king over Israel? fill thy horn with oil, and go: I will send thee to Jesse the Beth-lehemite; for I have provided me a king among his sons.

And it came to pass, when they were come, that he looked on Eliab, and said, Surely Jehovah’s anointed is before him. But Jehovah said unto Samuel, Look not on his countenance, or on the height of his stature; because I have rejected him: for Jehovah seeth not as man seeth; for man looketh on the outward appearance, but Jehovah looketh on the heart.

And Jesse made seven of his sons to pass before Samuel. And Samuel said unto Jesse, Jehovah hath not chosen these. And Samuel said unto Jesse, Are here all thy children? And he said, There remaineth yet the youngest, and, behold, he is keeping the sheep. And Samuel said unto Jesse, Send and fetch him; for we will not sit down till he come hither. And he sent, and brought him in. Now he was ruddy, and withal of a beautiful countenance, and goodly to look upon. And Jehovah said, Arise, anoint him; for this is he. Then Samuel took the horn of oil, and anointed him in the midst of his brethren: and the Spirit of Jehovah came mightily upon David from that day forward. So Samuel rose up, and went to Ramah.