Muhammad bin Ma'mar bin Rabi' محمد بن معمر بن ربعي القيسي البحراني · The Book of Fasting

"O Messenger of Allah, I am a man who fasts continually: shoud I fast when traveling?" He said: "Fast if you wish and break you fast if you wish." 'Ata said: "someone who heard him told me that Ibn 'Umar (said) that the Prophet said: 'Whoever fasts every day of his life, and then he has not fasted."

"There are four things which the Prophet never gave up: Fasting 'Ashura', (fasting during) the ten days, (fasting) three days of each month, and praying two Rak'ahs before Al-Ghadah (Fajr)."

"Ubayy said: 'A Bedouin came to the Messenger of Allah, and he had a rabbit that he had grilled and some bread. He placed it before the Prophet then he said: "I found it bleeding." The Messenger of Allah said to his Companions: "It doesn't matter; eat." And he said to the Bedouin: "Eat," He said: "I am fasting." He said: "If you want to fast then you should fast the shining days of Al-Bid: The thirteenth, fourteenth and fifteenth."