Sahih Muslim 1292
Sahih Muslim · Book 15: The Book of Pilgrimage · It is recommended to send the weak among women and others ahead from Al-Muzdalifah to Mina at the end of the night, before it gets crowded, but it is recommended for others to stay there until they have prayed Subh in Al-Muzdalifah
It is narrated from Umm Habiba:
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ ، حَدَّثَنَا عَمْرُو بْنُ دِينَارٍ ، ح وَحَدَّثَنَا عَمْرٌو النَّاقِدُ ، حَدَّثَنَا سُفْيَانُ ، عَنْ عَمْرِو بْنِ دِينَارٍ ، عَنْ سَالِمِ بْنِ شَوَّالٍ ، عَنْ أُمِّ، حَبِيبَةَ قَالَتْ كُنَّا نَفْعَلُهُ عَلَى عَهْدِ النَّبِيِّ صلى الله عليه وسلم نُغَلِّسُ مِنْ جَمْعٍ إِلَى مِنًى . وَفِي رِوَايَةِ النَّاقِدِ نُغَلِّسُ مِنْ مُزْدَلِفَةَ .
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)."