Musannaf Ibn Abi Shayba 34:305

Maslama narrated to us, Abu Ja’far Ahmad ibn Ibrahim ibn ‘Abd Allah ibn Muhammad ibn Yahya al-Mu’afiri al-Misri, known as Ibn Hamawayh, narrated to us in al-Fustat in the Mosque, dictating from his book in Dhu al-Qa’dah in the year three hundred and twenty-two, he said: al-Rabi’ ibn Sulayman al-Muradi narrated to us, Asad ibn Musa narrated to us, Hammad ibn Salama narrated to us, from Abu Qaza’a, from Hakim ibn Mu’awiya, he said: I heard the Messenger of Allah, may Allah bless him and grant him peace, saying: "You will be gathered walking and riding, and upon your faces you will be presented to Allah. Upon your mouths will be the *fidam* (a covering/muzzle), and the first thing that will speak about one of you is his thigh."