Muhammad bin Uthman asked al-Qasim bin Muhammad about the woman who has a prolonged flow of blood. He replied: She should abandon prayer during her menstrual period, then wash and pray ; then she should wash during her menstrual period.
Hadith Referenceسنن ابي داود / كتاب الطهارة / 303
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:إسناده صحيح, انفرد به ابو داود
Hadith Takhrij« تفرد به أبو داود، (تحفة الأشراف: 19205) (صحیح) »