ثُمَّ أَنزَلَ اللَّهُ سَكينَتَهُ عَلىٰ رَسولِهِ وَعَلَى المُؤمِنينَ وَأَنزَلَ جُنودًا لَم تَرَوها وَعَذَّبَ الَّذينَ كَفَروا ۚ وَذٰلِكَ جَزاءُ الكافِرينَ

Then, God sent down His tranquility upon His Messenger and the believers. He sent down forces you didn’t see and tormented those disbelieving. This is the compensation for the unbelievers.