1 Samuel 17:12-15

Now David was the son of a man named Jesse, an Ephrathite from Bethlehem in the land of Judah. Jesse was an old man at that time, and he had eight sons. Jesse’s three oldest sons—Eliab, Abinadab, and Shimea—had already joined Saul’s army to fight the Philistines. David was the youngest son. David’s three oldest brothers stayed with Saul’s army, but David went back and forth so he could help his father with the sheep in Bethlehem.