Arabic (Original)
وَبِهَذَا الْإِسْنَادِ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ لَوْ يَعْلَمُ الْمُؤْمِنُ مَا عِنْدَ اللَّهِ عَزَّ وَجَلَّ مِنْ الْعُقُوبَةِ مَا طَمِعَ بِجَنَّتِهِ أَحَدٌ وَلَوْ يَعْلَمُ الْكَافِرُ مَا عِنْدَ اللَّهِ مِنْ الرَّحْمَةِ مَا قَنَطَ مِنْ رَحْمَتِهِ أَحَدٌ.
English Translation
And with this chain of narration, the Prophet (peace be upon him) said: "If the believer knew what punishment Allah the Almighty has, no one would covet His Paradise. And if the disbeliever knew what mercy Allah has, no one would despair of His mercy."