Sahih Muslim Book 54, Hadith 29
Hudhaifa reported that Allah's Messenger (ﷺ) stood before us one day and he did not leave anything unsaid (that he had to say) at that very spot which would happen (in the shape of turmoil) up to the Last Hour. Those who had to remember them preserved them in their minds and those who could not remember them forgot them. My friends knew them and there are certain things which slip out of my mind, but I recapitulate them when anyone makes a mention of them just as a person is lost from one's mind but is recalled to him on seeing his face.
By Allah, I have the best knowledge amongst people about every turmoil which is going to appear in the period intervening me and the Last Hour; and it is not for the fact that Allah's Messenger (ﷺ) told me something confidentially pertaining to it and he did not tell anybody else about it, but it is because of the fact that I was present in the assembly in which he had been describing the turmoil. and he especially made a mention of three turmoils which would not spare anything and amongst these there would be turmoils like storms in the hot season. Some of them would be violent and some of them would be comparatively mild. Hudhaifa said: All (who were present) except I have gone (to the next world).
And he forgot who had to forget that and. he did not make a mention of what follows after this.