Sahih al-Bukhari 3251
Sahih al-Bukhari · Book 59: Beginning of Creation · The characteristics of Paradise, and the fact that it has already been created
Narrated Anas bin Malik:
حَدَّثَنَا رَوْحُ بْنُ عَبْدِ الْمُؤْمِنِ ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ ، حَدَّثَنَا سَعِيدٌ ، عَنْ قَتَادَةَ ، حَدَّثَنَا أَنَسُ بْنُ مَالِكٍ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِنَّ فِي الْجَنَّةِ لَشَجَرَةً يَسِيرُ الرَّاكِبُ فِي ظِلِّهَا مِائَةَ عَامٍ لاَ يَقْطَعُهَا " .
The Prophet (ﷺ) said, "There is a tree in Paradise (which is so big and huge that) if a rider travels in its shade for one hundred years, he would not be able to cross it."