1 Samuel 17:15 (KJV)

And the three eldest sons of Jesse went and followed Saul to the battle: and the names of his three sons that went to the battle were Eliab the firstborn, and next unto him Abinadab, and the third Shammah.

And David was the youngest: and the three eldest followed Saul.

But David went and returned from Saul to feed his father’s sheep at Beth–lehem.

And the Philistine drew near morning and evening, and presented himself forty days.

And Jesse said unto David his son, Take now for thy brethren an ephah of this parched corn, and these ten loaves, and run to the camp to thy brethren;