Fatimah bint Muhammad (who was raised by 'Amrah) said that a woman from the Quraysh sent a piece of cotton to 'Amrah, on which there was something yellowish, and asked: If a woman sees only such yellowness during her menstruation, is she considered pure? 'Amrah replied: No, not until the cotton comes out completely white (i.e., the woman is not pure yet).