Being clean and free of impure substances (najasah) is one of the essential conditions of prayer, and menstrual blood is impure in and of itself. In this hadith, Asma’ bint Abi Bakr al-Siddiq (may Allah be pleased with her) narrates that a woman came to the Prophet (blessings and peace of Allah be upon him) to ask him about a garment that becomes contaminated with menstrual blood. The Prophet (blessings and peace of Allah be upon him) instructed her to scratch it, meaning that she should rub it in order to remove the impurity. That applies if the blood has dried on the garment. Then she should rub it with water, meaning that she should rub it with her fingers whilst pouring water onto it, so that the stain that the garment had absorbed will be loosened and removed. Then she should sprinkle water on it, pouring water on it little by little, until the traces of blood are removed by washing it. After cleaning the garment in this manner, it will be permissible for her to pray in it. This hadith indicates that no specific number of times is stipulated in order to remove impurity by washing; rather what is required is simply to clean the garment. Then if any trace is left on it that is too difficult to remove, it may be overlooked. This is how Islam makes things easy for people. .