The Messenger of Allah ﷺ said, "In Paradise there is a tree so vast that a rider could travel in its shade for a hundred years and still not cross it."
حدثنا يزيد أخبرنا محمد عن أبي الزناد عن الأعرج
قال رسول الله ﷺ في الجنة شجرة يسير الراكب في ظلها مائة سنة لا يقطعها
Its chain of transmission is sahih. Muslim 2:349 also related it with a similar meaning, but did not mention its full wording, through the route of Mughira Hizami from Abu Zinad. Bukhari 481 related it through the route of Sufyan from Abu Zinad, with an addition at the end. Bukhari 6:233, Muslim 2:349, Tirmidhi 3:323, Tayalisi 2547, and Ibn Majah 4335 also related it through other routes from Abu Hurairah, at length and in brief, and it will likewise come in the Musnad at 9232, 9407, 9648, 9831, 9870, 9951, 10067, and 10264.