Musnad Ahmad 962:168

Yazid ibn Abd Rabbih narrated to us, Al-Walid ibn Muslim narrated to us, from Uthman ibn Abi al-Atikah, from Ali ibn Yazid, from al-Qasim, from Abu Umamah, from one who saw the Messenger of Allah (may Allah bless him and grant him peace): "He set out toward Mina on the Day of Tarwiyah, and by his side was Bilal, in whose hand was a staff with a garment upon it, with which he was shading the Messenger of Allah (may Allah bless him and grant him peace)."