The main part of this Medinan sura is a comment on the Battle of Badr (near Medina), the first fought between the Muslims and their Meccan opponents in the second year after the Migration. The Muslims, some of whom were at first reluctant to fight, won in spite of being vastly outnumbered, and began to question the distribution of the gains. The sura reminds them that it was God who brought about the victory. Verse 41 shows how the gains were to be distributed. It advises Muslims and comments on the role of the hypocrites and on those who always break their treaties (verse 56), ending with a statement about loyalties and alliances.
Source: The Qur’an (Oxford World’s Classics) by M. A. S. Abdel Haleem (Amazon Kindle Edition)