وَ بِهَذَا الْإِسْنَادِ عَنِ الْحُسَیْنِ بْنِ سَعِیدٍ عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ أَبِی بَصِیرٍ قَالَ: سَأَلْتُ أَبَا الْحَسَنِ ع عَنِ الصِّیَامِ فِی الشَّهْرِ کَیْفَ هُوَ فَقَالَ ثَلَاثَهُ أَیَّامٍ فِی الشَّهْرِ فِی کُلِّ عَشَرَهِ أَیَّامٍ یَوْماً إِنَّ اللَّهَ عَزَّ وَ جَلَّ یَقُولُ فِی کِتَابِهِ- مَنْ جاءَ بِالْحَسَنَهِ فَلَهُ عَشْرُ أَمْثالِها ثَلَاثَهُ أَیَّامٍ فِی الشَّهْرِ صَوْمُ الدَّهْرِ.
3. And from the previous chain from al-Hussain b. Sa’eed from Ahmad b. Muhammad from Abi Basir who said: The narrator asked Imam Musa Kadhim (a.s.), “How can one gain the reward of fasting for a month?” Imam (a.s.) replied, “By observing fast for three days of every month because the Almighty Allah has said that one who does a good deed would get ten rewards for it. Hence observing fast for three days of a month is equal to fasting for an age.”