It is narrated from Hazrat Anas bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: In Paradise, there is a tree such that if a rider were to travel under its shade for a hundred years, he would still not reach the end of its shade.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 12677