‘Alqama ibn Abi ‘Alqama related that his mother, the freed slave of ‘Aishah, mother of the Believers, said: The women used to send ‘Aishah, mother of the Believers, little boxes containing cotton with yellow post-menstrual discharge on it, asking her about prayer. And she would tell them: Do not be hasty until you see the cotton white; by this she meant full purity from menstruation.