1 Samuel 17:12-17

12Now David was the son of that Ephrathite of Bethlehem Judah, whose name was Jesse, and who had eight sons. And the man was old, advanced in years, in the days of Saul.

13The three oldest sons of Jesse had gone to follow Saul to the battle. The names of his three sons who went to the battle were Eliab the firstborn, next to him Abinadab, and the third Shammah.

14David was the youngest. And the three oldest followed Saul.

15But David occasionally went and returned from Saul to feed his father’s sheep at Bethlehem.

16And the Philistine drew near and presented himself forty days, morning and evening.

17Then Jesse said to his son David, “Take now for your brothers an ephah of this dried grain and these ten loaves, and run to your brothers at the camp.