When God promised that you will be triumphant over one of the two parties (the caravan who was carrying the Muslims’ confiscated wealth or the army which was marching to destroy the Muslims.) At that time you were wishing that the weaker party (the caravan carrying the wealth) would fall to you. However, it was the will of God to establish the truth (Islam) with His word and to cut across the root of the disbelievers (who were much stronger than the Muslims’ army.)