﴿ وَعَدَكُمُ ٱللَّهُ مَغَانِمَ كَثِيرَةًۭ تَأْخُذُونَهَا فَعَجَّلَ لَكُمْ هَٰذِهِۦ وَكَفَّ أَيْدِىَ ٱلنَّاسِ عَنكُمْ وَلِتَكُونَ ءَايَةًۭ لِّلْمُؤْمِنِينَ وَيَهْدِيَكُمْ صِرَٰطًۭا مُّسْتَقِيمًۭا ﴾

“[O you who believe!] God has promised you many war-gains which you shall yet achieve; and He has vouchsafed you these [worldly gains] well in advance, and has stayed from you the hands of [hostile] people, so that this [your inner strength] may become a symbol to the believers [who will come after you], and that He may guide you all on a straight way.”

(Allah promiseth you much booty that ye will capture) this is the booty of Persia which they had not captured yet but would capture a few years later, (and hath given you this) i.e. the booty of Khaybar (in advance, and hath withheld men's hands from you) from fighting you; referring here to Asad and Ghatafan who were allies of Khaybar, (that it) the conquest of Khaybar (may be a token) a lesson and sign (for the believers) this is because the believers were about 8,000 in number while Khaybar were about 70,000, (and that He may guide you on a right path) and that He may hold you firm on an established religion with which He is pleased.