Musannaf Ibn Abi Shayba 31:1

Marwan ibn Mu'awiyah narrated to us, from al-'Ala' ibn Khalid al-Asadi, from Shaqiq ibn Salamah, from Ibn Mas'ud regarding His saying: "And Hell will be brought on that Day," he said: It will be brought, being led by seventy thousand reins. With every rein there will be seventy thousand angels dragging it.