Abu Qatada reported,

Shuba said, "I asked Ghaylan al-Ansari," and he nodded with his head, meaning yes, that a man asked the Prophet ﷺ about his fasting and he became angry. So Umar said, "We are pleased," or he said, "We are pleased with Allah as Lord and with Islam as religion."He said, "I am certain he also said, 'and with Muhammad as Messenger, and with our pledge of allegiance as our pledge.'"Then Umar, or another man, stood up and said, "Messenger of Allah, what about a man who fasts perpetually?"He replied, "He has neither fasted nor broken his fast," or "He has not fasted and has not broken his fast."The man asked, "What about fasting two days and breaking fast one day?"He said, "Who can endure that?"The man asked, "Breaking fast two days and fasting one day?"He said, "I wish Allah would give us strength for that."The man asked, "Fasting one day and breaking fast one day?"He said, "That is the fast of my brother Dawud."The man asked, "Fasting on Mondays and Thursdays?"He said, "That is the day I was born and the day revelation was sent down to me."The man asked, "Fasting three days every month, and from Ramadan to Ramadan?"He said, "That is fasting all time and breaking fast all time."The man asked, "Fasting the day of Arafah?"He said, "It expiates the past year and the year to come."The man asked, "Fasting the day of Ashura?"He said, "It expiates the past year."

حدثنا يحيى بن سعيد حدثنا شعبة عن قتادة حدثنا غيلان بن جرير عن عبد الله بن معبد الزماني

عن أبي قتادة قال

شعبة قلت لغيلان الأنصاري فقال برأسه أي نعم أن رجلا سأل النبي ﷺ عن صومه فغضب فقال عمر رضيت أو قال رضينا بالله ربا وبالإسلام دينا قال ولا أعلمه إلا قد قال وبمحمد رسولا وببيعتنا بيعة قال فقام عمر أو رجل آخر فقال يا رسول الله رجل صام الأبد قال لا صام ولا أفطر أو ما صام وما أفطر قال صوم يومين وإفطار يوم قال ومن يطيق ذلك قال إفطار يومين وصوم يوم قال ليت الله عز وجل قوانا لذلك قال صوم يوم وإفطار يوم قال ذاك صوم أخي داود قال صوم الاثنين والخميس قال ذاك يوم ولدت فيه وأنزل علي فيه قال صوم ثلاثة أيام من كل شهر ورمضان إلى رمضان صوم الدهر وإفطاره قال صوم يوم عرفة قال يكفر السنة الماضية والباقية قال صوم يوم عاشوراء قال يكفر السنة الماضية