I Samuel 17:8-9

Then he stood and cried out to the armies of Israel, and said to them, “Why have you come out to line up for battle? Am I not a Philistine, and you the servants of Saul? Choose a man for yourselves, and let him come down to me. If he is able to fight with me and kill me, then we will be your servants. But if I prevail against him and kill him, then you shall be our servants and serve us.”