Abu Qataadah Radiyallahu 'Anhu reports that Rasulullah Sallallahu 'Alayhi Wasallam said:
"Whomsoever sees me, that is, in a dream, has seen that which is a fact". (IT)
App reference (IT): Book 56, Hadith 7 (IT)
English reference (IT): Book 55, Hadith 394 (IT)
Arabic reference (IT): Book 56, Hadith 412 (IT)