And David said unto Ahimelech, And is there not here under thine hand spear or sword? for I have neither brought my sword nor my weapons with me, because the king’s business required haste. (1 Samuel 21:8)
Seeing Doeg, David realized that he had left Gibeah so hastily that he had not had time to gather any weapons to protect himself in case of attack. As an outlaw he would be at the mercy of anyone who found him.