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". (ID)
App reference (ID): Book 56, Hadith 7 (ID)
English reference (ID): Book 55, Hadith 394 (ID)
Arabic reference (ID): Book 56, Hadith 412 (ID)