Hadeeth Qudsi 37:

On the authority of AbuHurayrah (may Allah be pleased with him), who said that the Messengerof Allah   said: Allah said:

I have prepared for My righteousservants what no eye has seen and no ear has heard, not has it occurredto human heart. Thus recite if you wish (1): And no soul knows what joyfor them (the inhabitants of Paradise) has been kept hidden (QuranChapter 32 Verse 17).

(1) The words “Thus recite if youwish” are those of Abu Harayrah.

It was related by al-Bukhari,Muslim, at-Tirmidhi and Ibn Majah.