Sahih Muslim Book 020, Hadith Number 4553.
Chapter : Instruction to stick to the main body of the Muslims in the time of trials and warning against those inviting people to disbelief.
It has been narrated on the authority of Hudhaifa b. al-Yaman who said: People used to ask the Messenger of Allah (may peace be upon him) about the good times, but I used to ask him about bad times fearing lest they overtake me. I said: Messenger of Allah, we were in the midst of ignorance and evil, and then God brought us this good (time through Islam). Is there any bad time after this good one? He said: Yes. I asked: Will there be a good time again after that bad time? He said: Yes, but therein will be a hidden evil. I asked: What will be the evil hidden therein? He said: (That time will witness the rise of) the people who will adopt ways other than mine and seek guidance other than mine. You will know good points as well as bad points. I asked: Will there be a bad time after this good one? He said: Yes. (A time will come) when there will be people standing and inviting at the gates of Hell. Whoso responds to their call they will throw them into the fire. I said: Messenger of Allah, describe them for us. He said: All right. They will be a people having the same complexion as ours and speaking our language. I said: Messenger of Allah, what do you suggest if I happen to live in that time? He said: You should stick to the main body of the Muslims and their leader. I said: If they have no (such thing as the) main body and have no leader? He said: Separate yourself from all these factions, though you may have to eat the roots of trees (in a jungle) until death comes to you and you are in this state.