كتاب الحج
15
The Book of Pilgrimage
(25)
Chapter: The pilgrim performing Qiran should not exit Ihram except when the pilgrims performing Ifrad exit Ihram
(25)
باب بَيَانِ أَنَّ الْقَارِنَ لاَ يَتَحَلَّلُ إِلاَّ فِي وَقْتِ تَحَلُّلِ الْحَاجِّ الْمُفْرِدِ ‏

Hafsa (Allah be pleased with her), the wife of Allah's Apostle (ﷺ), said:

Messenger of Allah. what about people who have put off Ihram whereas you have not put it off after your 'Umra? He said: I have stuck my hair and have driven my sacrificial animal, and would not, therefore, put off Ihram until I have sacrificed the animal.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ حَفْصَةَ، - رضى الله عنهم - زَوْجَ النَّبِيِّ صلى الله عليه وسلم قَالَتْ يَا رَسُولَ اللَّهِ مَا شَأْنُ النَّاسِ حَلُّوا وَلَمْ تَحْلِلْ أَنْتَ مِنْ عُمْرَتِكَ قَالَ ‏ "‏ إِنِّي لَبَّدْتُ رَأْسِي وَقَلَّدْتُ هَدْيِي فَلاَ أَحِلُّ حَتَّى أَنْحَرَ ‏"‏ ‏.‏
Reference : Sahih Muslim 1229 a
In-book reference : Book 15, Hadith 192
USC-MSA web (English) reference : Book 7, Hadith 2833
  (deprecated numbering scheme)