Sunan Abi Dawud Fasting (Kitab Al-Siyam) Abdul 'Aziz bin Muhammad al-Daruradi عبد العزيز بن محمد الدراوردي Abu Ja'far al-Nafaili عبد الله بن محمد أبو جعفر النفيلي الحران Safwan bin Slym al-Madni صفوان بن سليم المدني أبو عبد الله Umar bin Thabit عمر بن ثابت الأنصاري Da'if I asked or someone asked the Prophet (ﷺ) about perpetual fasting. He replied: You have a duty to your family. Fast during Ramadan and the following month, and every Wednesday and Thursday. You will then have observed a perpetual fast. https://parallelquran.com/hadith/sunan-abi-dawud-2432/