Imam Ibrahim Nakha'i, may Allah have mercy on him, said: If a woman experiences menstruation three times in one month or forty days, then? He said: Truthful and just women should testify that this has happened, so that prayer becomes forbidden for her due to menstruation, then its period is complete. Abu Muhammad Imam Darimi said: I heard Yazid bin Harun saying: I consider the period of purity to be fifteen days as correct.