And in the hadith of Ibn Abbas [it is mentioned] that Eve was caused by God to bleed twice in a month; what clarifies that the shortest [duration of] purity is less than fifteen days. Thus, he who assigned the duration of fifteen days for purity for all women is mistaken; this is because they said: 'The purity cannot be less than that for whoever has known menstrual cycles, or does not have known menstrual cycles.' So, every woman whose menstrual cycles are known in the months at a fixed time regarding her menstruation and purity, if she menstruates three times in a month, and she becomes pure at every menstrual period, then her 'iddah has completed. He means: if her menstruation and purity are as such, and the difference [of opinion] only concerns the one whose menstrual cycles increase and decrease.

598 - Ishaq narrated to us, saying: Isa ibn Yunus narrated to us, from Isma'il ibn Abi Khalid, from al-Sha'bi, that a woman came to Ali ibn Abi Talib and said: 'I was divorced, and I menstruated three times in a month?' Ali said to Shurayh: 'Give your verdict regarding her.' He said: 'Shall I give my verdict while you are present?' He said: 'Give your verdict regarding her.' He said: 'If she brings trustworthy women from her family whose religious commitment is acceptable, and they testify saying: "She indeed menstruated three times, [and] she became pure at every menstrual period," then she is believed.' Ali said: 'Qalon.' Isa said: 'In Roman [Byzantine Greek], it means: You are correct.'

599 - al-Musayyab ibn Wadih narrated to us, saying: Ibn al-Mubarak narrated to us, from Ibn Lahi'ah, from Khalid ibn Yazid, from 'Ata' - regarding a woman who was divorced and experienced three consecutive menstrual periods in a month, is she now permissible [for marriage]? - He said: 'Her menstrual cycles are what they [usually] were.'