David says, "I want to fight Goliath," and Saul tries to give him his armor, because Saul is thinking, "Oh, when you say 'fight Goliath,' you mean 'fight him in hand-to-hand combat,' infantry on infantry."
David diz: "Quero lutar com Golias" e Saul tenta dar-lhe a sua armadura, porque Saul está a pensar: "Quando dizes 'lutar com Golias',  queres dizer "lutar com ele num combate corpo a corpo", "infantaria contra infantaria".