The Book Pertaining to Paradise, Its Description, Its Bounties and Its Intimates (Kitab Al-Jannat wa Sifat Na'imiha wa Ahliha)
Muslim :: Book 40 : Hadith 6783
Sahl b. Sa'd as-Sa'idi reported: I was in the company of Allah's Messenger (may peace be upon him) that he gave a description of Paradise and then Allah's Apostle (may peace be upon him) concluded with these words: There would be bounties which the eye has not seen and the ear has not heard and no human heart has ever perceived them. He then recited this verse:" They forsake (their) beds, calling upon their Lord in fear and in hope, and spend out of what We have given them. So no soul knows what refreshment of the eyes is hidden for them: a reward for what they did" (xxxii. 16-17)