Deuteronomy 20:8

Fear. Such often occasion the loss of battles. Alexander sent away all who had not courage to follow him in his expeditions. (Curtius x.) The Rabbins condemn these faint-hearted soldiers to carry water, &c., for the army, to prepare the roads and places for encampments. (Calmet) --- But this seems contrary to the intention of the lawgiver, who sends them back to their houses.