From Ali ibn Ibrahim, from his father, from Ibn Mahbub, from Ali ibn Ri'ab, from Abu Ubaydah: Abu Abdillah عليه السلام said: "If a woman sees that she has become pure (from menstruation) during the time of prayer but delays performing Ghusl (ritual purification) until the time for another prayer begins, then she must make up the prayer she neglected. And if she becomes pure during the time of one prayer but delays performing it until the time for another prayer begins, and then she sees blood again, she must make up the prayer she neglected."