Sahih al-Bukhari, Book 81, Hadith 141 (In-Book) ⓘ
Narrated Sahl bin Sa'd: Allah's Messenger said, "In Paradise there is a tree so big that in its shade a rider may travel for one hundred years without being able to cross it."
وَقَالَ إِسْحَاقُ بْنُ إِبْرَاهِيمَ أَخْبَرَنَا الْمُغِيرَةُ بْنُ سَلَمَةَ، حَدَّثَنَا وُهَيْبٌ، عَنْ أَبِي حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ فِي الْجَنَّةِ لَشَجَرَةً يَسِيرُ الرَّاكِبُ فِي ظِلِّهَا مِائَةَ عَامٍ، لاَ يَقْطَعُهَا " .
also referenced under: Hadith 6552 (DarusSalam) & Volume 8, Book 76, Hadith 559 (USC-MSA)