Abu Huraira reported Allah's Messenger (ﷺ) said that Allah, the Exalted and Glorious, said:
I have prepared for My pious servants which the eye has seen not, and the ear has heard not and no human heart has ever perceived such bounties leaving aside those about which Allah has informed you. He then recited:" No soul knows what comfort has been hidden for thein".
Reference: Sahih Muslim 2824 c
In-book reference: Book 53, Hadith 5
USC-MSA web (English) reference(deprecated numbering scheme): Book 40, Hadith 6782