The three eldest sons of Jesse had gone after Saul to the battle: and the names of his three sons who went to the battle were Eliab the firstborn, and next to him Abinadab, and the third Shammah.
And so David's brother Eliab saw David's interest in this thing, and he said to David, "Who's watching over your sheep back there in the wilderness kid? You better get on home in a hurry. I know your heart, you're just-dad probably didn't send you down here. You're just down to see what a war looks like and you go home in a hurry." His big brother is trying to sort of protect him.