1 Samuel 17:25-28

25Now the Israelites had been saying, “Do you see how this man keeps coming out? He comes out to defy Israel. The king will give great wealth to the man who kills him. He will also give him his daughter in marriage and will exempt his family from taxes in Israel.”

26David asked the men standing near him, “What will be done for the man who kills this Philistine and removes this disgrace from Israel? Who is this uncircumcised Philistine that he should defy the armies of the living God?”

27They repeated to him what they had been saying and told him, “This is what will be done for the man who kills him.”

28When Eliab, David’s oldest brother, heard him speaking with the men, he burned with anger at him and asked, “Why have you come down here? And with whom did you leave those few sheep in the wilderness? I know how conceited you are and how wicked your heart is; you came down only to watch the battle.”