After Allah mentioned the sins of the hypocrites, He praised the faithful believers and described their reward in the Hereafter,

لَـكِنِ الرَّسُولُ وَالَّذِينَ ءَامَنُواْ مَعَهُ جَـهَدُواْ

(But the Messenger and those who believed with him strove hard and fought) until the end of these two Ayat 9:88-89. This describes the qualities, as well as, the reward of faithful believers. Allah said,

The expression: اُولُوا الطَّولِ (ulu 'at-caul: translated as ` the capable ones' ) (86) is not for particularization. Instead, it serves a purpose. It tells that there were others too, the ones not so capable. And the incapable ones had, at least, some obvious excuse to stay behind.