Musannaf Ibn Abi Shayba 37:162

Ahmad ibn Ishaq narrated to us, he said: Wuhayb narrated to us, he said: Abdullah ibn Tawus narrated to us, from his father, from Abu Hurayrah, from the Prophet, may Allah bless him and grant him peace, who said: "Today, something like this has been opened from the barrier of Gog and Magog," and Wuhayb made a knot with his hand [representing] ninety.