1 Samuel 17:12-15

Now David was the son of that Ephrathite of Beth-lehem-judah, whose name was Jesse; and he had eight sons: and the man was an old man in the days of Saul, stricken in years among men. And the three eldest sons of Jesse had gone after Saul to the battle: and the names of his three sons that went to the battle were Eliab the first-born, and next unto him Abinadab, and the third Shammah. And David was the youngest; and the three eldest followed Saul. Now David went to and fro from Saul to feed his father’s sheep at Beth-lehem.