وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرٍ، عَنْ أَبِيهِ، أَنَّ أَبَا سَلَمَةَ بْنَ عَبْدِ الرَّحْمَنِ، أَخْبَرَهُ أَنَّ أُمَّ سُلَيْمٍ بِنْتَ مِلْحَانَ اسْتَفْتَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم وَحَاضَتْ - أَوْ وَلَدَتْ - بَعْدَ مَا أَفَاضَتْ يَوْمَ النَّحْرِ فَأَذِنَ لَهَا رَسُولُ اللَّهِ صلى الله عليه وسلم فَخَرَجَتْ ‏.‏

Yahya related to me from Malik from Abdullah ibn Abi Bakr fromhis father that Abu Salama ibn Abd ar-Rahman told him that Umm Sulaymbint Milhan asked the Messenger of Allah, may Allah bless him andgrant him peace, for advice one time when she had begun menstruating,or had given birth to a child after she had done tawaf al-ifada on theDay of Sacrifice. The Messenger of Allah, may Allah bless him andgrant him peace, gave her permission to leave. Malik said, "Awoman menstruating at Mina stays until she has done tawaf of theHouse. There is no escape from that for her. If she has already donethe tawaf al-ifada and she starts to menstruate afterwards, she mayleave for her country, since permission for the menstruating women toleave has been transmitted to us from the Messenger of Allah, mayAllah bless him and grant him peace." He added, "If a womanstarts her period at Mina before she does the tawaf al-ifada, and theperiod lasts longer than usual, she has to stay longer than the timethat bleeding would usually detain women." Translation Not Available

Book Ref: Muwatta Imam Malik Book 20 Hadith 936
Web Ref:  Muwatta Imam Malik Book 20 Hadith 238