Chapter on Menstruation, Istihada (abnormal bleeding), and Nifas (postpartum bleeding)

From Ibn Mahbub, from Ali ibn Ri’ab, from Ubayd ibn Zurarah: Abu Abdillah عليه السلام said: "Any woman who sees that she has become pure (from menstruation) and is capable of performing Ghusl (ritual purification) during the time of a prayer but neglects it until the time for another prayer begins, then she must make up the prayer she neglected. However, if she sees that she has become pure during the time of a prayer and begins preparing for it, and the time of the prayer passes and the time for another prayer begins, then there is no obligation upon her to make up the missed prayer. Instead, she should pray the one whose time has started."