[Machine] "If a woman has her period for a month or forty nights, then three menstrual cycles, and reliable witnesses among women testify that she has seen what prohibits her from praying, which is the menstrual impurity that is known as menstruation, then her waiting period is complete. Abu Muhammad said, "I heard Yazid ibn Harun say, 'I prefer purity for fifteen days.'"  

إِذَا حَاضَتِ الْمَرْأَةُ فِي شَهْرٍ أَوْ فِي أَرْبَعِينَ لَيْلَةً ثَلَاثَ حِيَضٍ قَالَ فَإِذَا شَهِدَ لَهَا الشُّهُودُ الْعُدُولُ مِنَ النِّسَاءِ أَنَّهَا رَأَتْ مَا يُحَرِّمُ عَلَيْهَا الصَّلَاةَ مِنْ طُمُوثِ النِّسَاءِ الَّذِي هُوَ الطَّمْثُ الْمَعْرُوفُ فَقَدْ خَلَا أَجَلُهَا قَالَ أَبُو مُحَمَّدٍ سَمِعْتُ يَزِيدَ بْنَ هَارُونَ يَقُولُ أَسْتَحِبُّ الطُّهْرَ خَمْسَ عَشْرَةَ