Musnad Ahmad 26:157

Waki’ narrated to us, from al-Mas’udi, from Uthman al-Thaqafi, or al-Hasan ibn Sa’d—al-Mas’udi was in doubt—from ‘Abdah al-Nahdi, from Abdullah ibn Mas’ud, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, Allah has not prohibited a prohibition except that He knew that someone among you would eventually approach it. Behold, I am holding onto your waistbands so that you do not fall into the Fire like the falling of moths or flies."