1 Samuel 17:29

David spoke to the men who stood by him, saying, “What shall be done to the man who kills this Philistine and takes away the reproach from Israel? For who is this uncircumcised Philistine, that he should defy the armies of the living God?”

The people answered him in this way, saying, “So shall it be done to the man who kills him.”

Eliab his oldest brother heard when he spoke to the men; and Eliab’s anger burned against David, and he said, “Why have you come down? With whom have you left those few sheep in the wilderness? I know your pride and the evil of your heart; for you have come down that you might see the battle.”

He turned away from him toward another, and spoke like that again; and the people answered him again the same way.

When the words were heard which David spoke, they rehearsed them before Saul; and he sent for him.

David said to Saul, “Let no man’s heart fail because of him. Your servant will go and fight with this Philistine.”