1 Samuel 17:5-15

He had a bronze helmet on his head, and he was clothed with scale-armor which weighed five thousand shekels of bronze. He also had bronze greaves on his legs and a bronze javelin slung between his shoulders. The shaft of his spear was like a weaver’s beam, and the head of his spear weighed six hundred shekels of iron; his shield-carrier also walked before him. He stood and shouted to the ranks of Israel and said to them, “Why do you come out to draw up in battle array? Am I not the Philistine and you 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 become your servants; but if I prevail against him and kill him, then you shall become our servants and serve us.” Again the Philistine said, “I defy the ranks of Israel this day; give me a man that we may fight together.” When Saul and all Israel heard these words of the Philistine, they were dismayed and greatly afraid. Now David was the son of the Ephrathite of Bethlehem in Judah, whose name was Jesse, and he had eight sons. And Jesse was old in the days of Saul, advanced in years among men. The three older sons of Jesse had gone after Saul to the battle. And the names of his three sons who went to the battle were Eliab the firstborn, and the second to him Abinadab, and the third Shammah. David was the youngest. Now the three oldest followed Saul, but David went back and forth from Saul to tend his father’s flock at Bethlehem.