وَقَمَعْتَ نَفْسَكَ وَهِيَ أَكْبَرُ أَعْدَائِكَ؟
And why have you not restrained your own self, though it is your greatest enemy?
Qamaʿa means to suppress or restrain rebellion. Nafs here points to unruly impulses that draw a person into error; the image need not imply that every natural human desire is intrinsically wrong.
The statement wa-hiya akbaru aʿdāʾika gives the reason for the appeal. Real reform may require confronting internal resistance, not merely outside opponents.