What does 1 Samuel 17:39 mean?
David and Saul have agreed: David will go out onto the field of battle and accept Goliath's challenge. Thiers will be a fight to the death to decide the outcome of the battle (1 Samuel 17:1–10, 31–37). To prepare the young man, the king is providing his own armor as protection against the intimidating Philistine champion (1 Samuel 17:38). This may have been an attempt to intimidate the enemy by showing kingly armor; Saul is far too tall for the armor to fit David (1 Samuel 9:2).Saul's helmet and heavy chain mail have been placed on David. Now David straps Saul's sword on top of the armor and begins to move around in the gear. But it is not comfortable. Presumably, David has never been trained for combat in armor; he's also not worn this specific armor before. David wisely sees Saul's armor as a hindrance rather than a help, and he decides not to wear any of it. He had no armor when he fought dangerous animals (1 Samuel 17:34–35), he won't be helped by it now.