﴿ أَفَلَمْ يَسِيرُوا۟ فِى ٱلْأَرْضِ فَيَنظُرُوا۟ كَيْفَ كَانَ عَٰقِبَةُ ٱلَّذِينَ مِن قَبْلِهِمْ ۚ كَانُوٓا۟ أَكْثَرَ مِنْهُمْ وَأَشَدَّ قُوَّةًۭ وَءَاثَارًۭا فِى ٱلْأَرْضِ فَمَآ أَغْنَىٰ عَنْهُم مَّا كَانُوا۟ يَكْسِبُونَ ﴾

“HAVE THEY, then, never journeyed about the earth and beheld what happened in the end to those [deniers of the truth] who lived before their time? More numerous were they, and greater in power than they are, and in the impact which they left on earth: but all that they ever achieved was of no avail to them –”

In verse 77, it was said: فَاصْبِرْ‌ إِنَّ وَعْدَ اللَّـهِ حَقٌّ فَإِمَّا نُرِ‌يَنَّكَ (Therefore, be patient. Surely, the promise of Allah is true. Then, whether We show you [ in your life ] a part of the promise We are making to them, or make you die [ before they are punished ], in any case they have to be returned to Us). From this verse it appears that the Holy Prophet ﷺ was hopefully waiting for the disbelievers to be punished. Therefore, it was to comfort him that he was asked to be somewhat patient about it. The promise of Allah for them, that they will be punished, will certainly be fulfilled - may be during his lifetime, or after he has departed from the mortal world. Waiting for the disbelievers to be punished apparently seems contrary to the dignity of one who was sent with universal mercy. But, here the matter is different. When the purpose of punishing criminals is to bring comfort to innocent believers who were oppressed, then, the punishment of criminals is not contrary to compassion and mercy. Nobody regards the punishment given to a criminal against the dictate of mercy.