Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Verily, in Paradise, there is a tree that the rider of a lean, swift horse would travel for a hundred years without reaching its end."
Authentic - Agreed upon
The Prophet (may Allah's peace and blessings be upon him) informed that in Paradise, there is a tree under which a rider on a horse, prepared for fast racing, would travel for a hundred years without reaching the end of its branches.
Daga Cikin Fa idodin Hadisin
Demonstrating the vastness of Paradise and the greatness of its trees.