قُلْ هَلْ تَرَبَّصُونَ بِنَآ إِلَّآ إِحْدَى ٱلْحُسْنَيَيْنِ ۖ وَنَحْنُ نَتَرَبَّصُ بِكُمْ أَن يُصِيبَكُمُ ٱللَّهُ بِعَذَابٍ مِّنْ عِندِهِۦٓ أَوْ بِأَيْدِينَا ۖ فَتَرَبَّصُوٓا۟ إِنَّا مَعَكُم مُّتَرَبِّصُونَ
Commentary:
The "two good things" referred to in this verse are martyrdom and victory. Only one of these two things can fall to the lot of believers in a war. Either they win and triumph or they die on the battlefield and become martyrs. Hence, the evil desires which the disbelievers and hypocrites entertained concerning the Muslims could never be fulfilled. The verse thus purports to say that true believers can never suffer a defeat; they either die fighting and thus win martyrdom or they return victorious from the field of battle.
A true Muslim either dies fighting or wins victory. There is no other alternative left to him.