1 Samuel 17:12-13

12Now David was the son of that Ephrathite of Bethlehem-Judah whose name was Jesse; and he had eight sons; and the man was old in the days of Saul, advanced [in years] among men.

13And the three eldest of the sons of Jesse had gone and followed Saul to the battle; and the names of his three sons that went to the battle were Eliab the firstborn, and the second to him Abinadab, and the third Shammah.