It is narrated from Imam Hasan, may Allah have mercy on him, regarding women in the state of nifas (postnatal bleeding) that they will refrain from prayer for forty days. If they become pure within forty days, that is fine; otherwise, they will refrain from prayer for another five or six days. (After 45 days) if they become pure, that is fine; otherwise, they will refrain from prayer for another period from 45 to 50 days. Then, if they become pure, that is fine; otherwise, they will be counted among those with istihada (irregular bleeding).