Musnad Ahmad 1157:0

Zaynab bint Jahsh (may Allah be pleased with her) reported that the Prophet (peace and blessings of Allah be upon him) entered upon her in a state of panic, saying: "There is no god but Allah. Woe to the Arabs from an evil that has drawn near. Today, a hole has been opened in the barrier of Gog and Magog like this," and he made a circle with his thumb and index finger. Zaynab bint Jahsh said: I said, "O Messenger of Allah, shall we be destroyed while there are righteous people among us?" He said: "Yes, if wickedness increases."