The Prophet (ﷺ) said, "A hole has been opened in the dam of Gog and Magog." Wuhaib (the sub-narrator) made the number 90 (with his index finger and thumb).
Sahih al-Bukhari Book 92, Hadith 83
← Previous Hadith That one day Allah's Messenger (ﷺ) entered upon her in a state of fear and said, "None has the right to be worshipped but Allah! Woe to the Arabs from the Great evil that has approached (them). Today a hole has been opened in the dam of Gog and Magog like this." The Prophet (ﷺ) made a circle with his index finger and thumb. Zainab bint Jahsh added: I said, "O Alllah's Apostle! Shall we be destroyed though there will be righteous people among us?" The Prophet (ﷺ) said, "Yes, if the (number) of evil (persons) increased."

Sahih al-Bukhari Book 92, Hadith 82 Next Hadith → Allah's Messenger (ﷺ) said, "Whoever obeys me, obeys Allah, and whoever disobeys me, disobeys Allah, and whoever obeys the ruler I appoint, obeys me, and whoever disobeys him, disobeys me."

Sahih al-Bukhari Book 93, Hadith 1