Sahih Al Bukhari 1: Chapter 3, Hadith 116

(116) To speak about (religious) knowledge at night

حَدَّثَنَا سَعِيدُ بْنُ عُفَيْرٍ، ‏‏‏‏‏‏قَالَ:‏‏‏‏ حَدَّثَنِي اللَّيْثُ، ‏‏‏‏‏‏قَالَ:‏‏‏‏ حَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ خَالِدِ، ‏‏‏‏‏‏عَنِ ابْنِ شِهَابٍ، ‏‏‏‏‏‏عَنْ سَالِمٍ، ‏‏‏‏‏‏قَالَ:‏‏‏‏ صَلَّى بِنَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْعِشَاءَ فِي آخِرِ حَيَاتِهِ، ‏‏‏‏‏‏فَلَمَّا سَلَّمَ قَامَ، ‏‏‏‏‏‏فَقَالَ:‏‏‏‏ "أَرَأَيْتَكُمْ لَيْلَتَكُمْ هَذِهِ، ‏‏‏‏‏‏فَإِنَّ رَأْسَ مِائَةِ سَنَةٍ مِنْهَا لَا يَبْقَى مِمَّنْ هُوَ عَلَى ظَهْرِ الْأَرْضِ أَحَدٌ".

SAHIH HADITH:

Narrated `Abdullah bin `Umar: Once the Prophet led us in the `Isha' prayer during the last days of his life and after finishing it (the prayer) (with Taslim) he said: Do you realize (the importance of) this night? Nobody present on the surface of the earth tonight will be living after the completion of one hundred years from this night.

REFERENCE:

Sahih Al Bukhari 1: Chapter 3, Hadith 116