1 Samuel 17:13

And the three eldest sons of Jesse went and followed Saul to
the battle
Either of their own accord, or rather at their father's motion, or however with his knowledge and consent, who because he could not go himself, willed them to go; and these were forward, and some of the foremost that followed Saul to the battle, being zealous and well disposed to defend their king and country:

and the names of the three sons that went to the battle were Eliab the
firstborn, and next unto him Abinadab, and the third Shammah;
who are the three mentioned by name that passed before Samuel, when he came to anoint one of Jesse's sons to be king, ( 1 Samuel 16:6 1 Samuel 16:8 1 Samuel 16:9 ) .