Muhammad b. al-Hasan b. Ahmad b. al-Walid narrated to us. He said: Muhammad b. al-Hasan al-Saffar narrated to us from Ya`qub b. Yazid from Muhammad b. Sinan from Ghiyath b. Ibrahim from al-Sadiq Ja`far b. Muhammad from his father from his forefathers . He said:

The Messenger of Allah (s) said: Whoever fasts a day piously, seeking the reward of Allah, forgiveness becomes obligatory for him.