It will be useful to explain the statement: ثُمَّ أَنزَلَ اللَّـهُ سَكِينَتَهُ عَلَىٰ رَسُولِهِ وَعَلَى الْمُؤْمِنِين (Then Allah sent down His tranquility upon His Messenger and upon the believers) appearing in verse 26 a little further. It means that Allah Ta` ala sent down His tranquility upon the hearts of the noble Companions who had lost their foothold on the battlefield during the initial attack of the enemy at Hunain. This caused their feet to become firm again and those who had run away came back. As for the sending of tranquility upon the Holy Prophet ﷺ and the Companions ؓ who had stayed on the war front with firmness and determination, it means that they could see victory close at hand. And since the tranquility mentioned here was of two kinds - one for those who ran, and the other for those who stayed on with the Holy Prophet ﷺ with firmness and determination - it is to point out to this refinement that the expressions: عَلَىٰ رَسُولِهِ وَعَلَى الْمُؤْمِنِين (...upon His Messenger and upon the believers) have been placed separately and introduced one after the other with the repetition of the preposition علی ) ’ ala: upon).
After that, it was said: وَأَنزَلَ جُنُودًا لَّمْ تَرَوْهَا (... and sent down forces which you did not see). This means that the people at large did not see. That some reports mention the ` seeing' of these ` forces' should not be taken as contrary to this.
After that, in conclusion, it was said: وَعَذَّبَ الَّذِينَ كَفَرُوا ۚ وَذَٰلِكَ جَزَآءُ الْكَافِرِينَ. It means that Allah punished those who disbelieved - and those who disbelieved deserved that punishment. This punishment or recompense refers to their subjugation at the hands of Muslims which was some-thing witnessed openly. In sum, what was their worldly punishment, they received promptly. As for their fate in the Hereafter, it has been mentioned in verse 27: