Musnad Ahmad Hadith 22537

It is narrated from Abu Qatadah (may Allah be pleased with him) that a man asked the Holy Prophet (ﷺ) about his fasting, so the Holy Prophet (ﷺ) became displeased. Seeing this, Umar (may Allah be pleased with him) said, "We are pleased with Allah as our Lord, Islam as our religion, and Muhammad (ﷺ) as our Messenger, and upon this we have pledged allegiance." Then another man or Umar (may Allah be pleased with him) himself stood up and asked, "O Messenger of Allah! If a person fasts continuously, what is the ruling?" The Holy Prophet (ﷺ) said, "His fasting and not fasting are both the same." The questioner asked, "How about fasting two days and leaving one day?" The Holy Prophet (ﷺ) said, "Who has the strength for that?" The questioner asked, "How about leaving two days and fasting one day?" The Holy Prophet (ﷺ) said, "Perhaps this is praiseworthy in the sight of Allah." The questioner asked, "How about fasting one day and leaving one day?" The Holy Prophet (ﷺ) said, "That is the way of my brother, Dawood (peace be upon him)." The questioner asked about fasting on Mondays and Thursdays. The Holy Prophet (ﷺ) said, "On that day I was born and on that day revelation was sent down to me. Fasting three days in every month and fasting the whole month of Ramadan is equal to fasting always." The questioner asked, "What is the ruling of fasting on the Day of Arafah?" The Holy Prophet (ﷺ) said, "It is an expiation for the sins of the previous and coming year." The questioner asked about the ruling of fasting on the Day of Ashura, so he said, "It is an expiation for the sins of the previous year."