Sahih Muslim 2827, 2828
The Book of Paradise, its Description, its Bounties and its Inhabitants
In Paradise There Is A Tree In Whose Shade A Rider Could Travel For One Hundred Years And Still Not Cross It
Sahl b. Sa'd reported Allah's Messenger (ﷺ) as saying: In Paradise, there is a tree under the shadow of which a rider can travel for a hundred years without covering (the distance) completely. This hadith has also been transmitted on the authority of Abu Sa'id al-Khudri that Allah's Messenger (ﷺ) is reported to have said: In Paradise, there is a tree under the shadow of which a rider of a fine and swift-footed horse would travel for a hundred years without covering the distance completely. There would be the pleasure of Allah for the inmates of Paradise and He would never be annoyed with them.