كتاب الحج
15  
The Book of Pilgrimage
(49)
Chapter: 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
(49)
باب اسْتِحْبَابِ تَقْدِيمِ دَفْعِ الضَّعَفَةِ مِنَ النِّسَاءِ وَغَيْرِهِنَّ مِنْ مُزْدَلِفَةَ إِلَى مِنًى فِي أَوَاخِرِ اللَّيَالِي قَبْلَ زَحْمَةِ النَّاسِ وَاسْتِحْبَابِ الْمُكْثِ لِغَيْرِهِمْ حَتَّى يُصَلُّوا الصُّبْحَ بِمُزْدَلِفَةَ
Sahih Muslim 1295

Salim b. 'Abdullah reported that 'Abdullah b. 'Umar (Allah be pleased with them) used to send ahead of him the weak members of his household to stay during the night at Mash'ar al-Haram at Muzdalifa. They remembered Allah so long as they could afford, and then they proceeded before the stay of the Imam, and before his return. So some of them reached Mina for the dawn prayer and some of them reached there after that; and as they reached there, they stoned al-Jamra; and Ibn 'Umar (Allah be pleased with them) used to say:

Allah's Messenger (ﷺ) has granted this concession to them.
وَحَدَّثَنِي أَبُو الطَّاهِرِ، وَحَرْمَلَةُ بْنُ يَحْيَى، قَالاَ أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، أَنَّ سَالِمَ بْنَ عَبْدِ اللَّهِ، أَخْبَرَهُ أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ كَانَ يُقَدِّمُ ضَعَفَةَ أَهْلِهِ فَيَقِفُونَ عِنْدَ الْمَشْعَرِ الْحَرَامِ بِالْمُزْدَلِفَةِ بِاللَّيْلِ فَيَذْكُرُونَ اللَّهَ مَا بَدَا لَهُمْ ثُمَّ يَدْفَعُونَ قَبْلَ أَنْ يَقِفَ الإِمَامُ وَقَبْلَ أَنْ يَدْفَعَ فَمِنْهُمْ مَنْ يَقْدَمُ مِنًى لِصَلاَةِ الْفَجْرِ وَمِنْهُمْ مَنْ يَقْدَمُ بَعْدَ ذَلِكَ فَإِذَا قَدِمُوا رَمَوُا الْجَمْرَةَ وَكَانَ ابْنُ عُمَرَ يَقُولُ أَرْخَصَ فِي أُولَئِكَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏.‏
Reference : Sahih Muslim 1295
In-book reference : Book 15, Hadith 334
USC-MSA web (English) reference : Book 7, Hadith 2969
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