Hadeeth Qudsi 29:

On the authority of AbuHurayrah (may Allah be pleased with him), who said that the Messengerof Allah  said: Allah (mighty and sublime be He) says:

My faithful servant’s reward fromMe, if I have taken to Me his best friend from amongst the inhabitantsof the world and he has then borne it patiently for My sake, shall benothing less than Paradise.

It was related by al-Bukhari.