`Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that Sayyiduna Abu Talhah (may Allah be pleased with him) did not observe (voluntary) fasts during the time of the Prophet Muhammad (peace and blessings be upon him) due to participating in jihad (so that his strength would not diminish). Then, when the Prophet Muhammad (peace and blessings be upon him) passed away, I never saw him leaving the fast except on the days of Eid al-Fitr and Eid al-Adha.