That the battle may be decided by us two alone. Such offers were frequent in those times. And possibly he thought the valiant Jonathan, who had assaulted a whole army, would never have refused this challenge. But God so ordered the matter, that none should accept it, because he would reserve this honour for David, as a step to his kingdom.
Related Commentaries of 1 Samuel 17:8
1 Samuel 17:8
8 And he stood and cried unto the armies of Israel, and said unto them, Why are ye come out to set your battle in array? am not I a Philistine, and ye servants to Saul? choose you a man for you, and let him come down to me.