Zainab (May Allah be pleased with her) reported:
The Prophet (ﷺ) came to visit me one day frightened and he (ﷺ) said: "La ilaha illallah (There is no true God but Allah). Woe to the Arabs because of an evil which hasdrawn near! Today an opening of this size has been made in the barrier restraining Ya'juj and Ma'juj (Gog andMagog people)." And he (ﷺ) made a circle with his thumb and index finger. I said, "O Messenger of Allah!Shall we perish while still there will be righteous people among us?'' He (ﷺ) replied, "Yes, when wickednessprevails".[Al-Bukhari and Muslim].
Arabic/English book reference: Book 1, Hadith 189