Musnad Ahmad 30:3129

Surayj narrated to us, Fulayh ibn Sulayman narrated to us, Hilal ibn Ali narrated to us, from Abd al-Rahman ibn Abi Amrah, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, in Paradise there is a tree in whose shade a rider travels for one hundred years. Read, if you wish: {And shade extended} [Al-Waqi'ah: 30]."