1 Samuel 17:8-12
8And 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.
9If he be able to fight with me, and to kill me, then will we be your servants: but if I prevail against him, and kill him, then shall ye be our servants, and serve us.
10And the Philistine said, I defy the armies of Israel this day; give me a man, that we may fight together.
11When Saul and all Israel heard those words of the Philistine, they were dismayed, and greatly afraid.
12Now David was the son of that Ephrathite of Bethlehemjudah, whose name was Jesse; and he had eight sons: and the man went among men for an old man in the days of Saul.
(KJV)