Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 2964
It is narrated from Umm Habiba: We used to set forth from Muzdalifa to Mina, (very early in the dawn) when it was dark. And in the narration of Naqid (the words are):" We set from Muzdalifa in the darkness (of the dawn)."