He said that the Prophet used to fast on Mondays and Thursdays, and when someone remarked on this to him he said, “On Monday and Thursday God forgives every Muslim except two who are at variance, for He says they must be left till they make peace with one another.”
He reported God’s messenger as saying, “If anyone out of a desire to please God fasts for a day, God will remove him from jahannam as far as a crow flies from the time it is a young bird till it dies of old age.”
Ahmad transmitted it, and Baihaqi transmitted it in Shu'ab al-iman from Salama b. Qais.
Ibn ‘Abbas said that it was the custom of God’s messenger not to eat on the middle days* of the month whether travelling or not.
*Literally, the days of the white (nights). These are the days following the thirteenth, fourteenth, and fifteenth nights of the month, the nights when there is most moonlight.
