From Sahih Muslim (Hadith 7280):
Mustaurid Qurashi reported:I heard Allah's Messenger (ﷺ) as saying: The Last Hour would come when the Romans would form a majority amongst people. This reached 'Amr b. al-'As and he said: What are these ahadith which are being transmitted from you and which you claim to have heard from Allah's Messenger (ﷺ)? Mustaurid said to him: I stated only that which I heard from Allah's Messenger (ﷺ). Thereupon 'Amr said: If you state this (it is true), for they have the power of tolerance amongst people at the time of turmoil and restore themselves to sanity after trouble, and are good amongst people so far as the destitute and the weak are concerned
Reference: Muslim 7280