Abu Dawud
The Rites of Hajj
Book Number: 004 / Hadith Number: 1810
Narated By as-Sa'ib al-Ansari : Khalid ibn as-Sa'ib al-Ansari on his father's authority reported the Apostle of Allah (pbuh) as saying: Gabriel came to me and commanded me to order my Companions to raise their voices in talbiyah.