"I asked the Messenger of Allah about fasting and he said: 'Fast one day of the month.' I said: 'Fast one day of the month.' I said: 'O Messenger of Allah, let me do more, let me do more.' He said: 'Let me do more, let mo do more; I am able for it.' Then the Messenger of Allah fell silent until I thought that he was going to refuse my request. Then he said: 'fast three days of each month."' (Using translation from Nasāʾī 2433)  

سَأَلْتُ رَسُولَ اللهِ ﷺ عَنِ الصَّوْمِ فَقَالَ «صُمْ يَوْمًا مِنَ الشَّهْرِ» قُلْتُ يَا رَسُولَ اللهِ زِدْنِي قَالَ يَقُولُ رَسُولُ اللهِ ﷺ «زِدْنِي زِدْنِي صُمْ يَوْمَيْنِ مِنْ كُلِّ شَهْرٍ» قُلْتُ يَا رَسُولَ اللهِ إِنِّي أَجِدُنِي قَوِيًّا فَقَالَ رَسُولُ اللهِ ﷺ «زِدْنِي زِدْنِي إِنِّي أَجِدُنِي قَوِيًّا» فَسَكَتَ رَسُولُ اللهِ ﷺ حَتَّى ظَنَنْتُ أَنَّهُ لَنْ يَزِيدَنِي قَالَ «صُمْ ثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ»  

"Fast one day of each month." He asked him for more, saying: "May my father and mother be ransomed for you, I am able." He said: "Fast two days of each month." He said" May my father and mother be sacrificed for you, O Messenger of Allah, I am able." The Messenger of Allah said: "I am able, I am able." He did not want to increase it, but when I insisted, the Messenger of Allah said: "Fast three days of each month." (Sahih) The end of what the Shaikh had about fasting, all praise is due to Allah the Lord of the worlds. (Using translation from Nasāʾī 2434)   

أَنَّهُ سَأَلَ النَّبِيَّ ﷺ عَنِ الصَّوْمِ فَقَالَ «صُمْ يَوْمًا مِنْ كُلِّ شَهْرٍ» فَاسْتَزَادَهُ وَقَالَ بِأَبِي أَنْتَ وَأُمِّي أَجِدُنِي قَوِيًّا فَزِدْنِي فَقَالَ رَسُولُ اللهِ ﷺ «إِنِّي أَجِدُنِي قَوِيًّا إِنِّي أَجِدُنِي قَوِيًّا» فَمَا كَادَ أَنْ يَزِيدَهُ فَاسْتَزَادَهُ فَزَادَهُ فَقَالَ «صُمْ يَوْمَيْنِ مِنْ كُلِّ شَهْرٍ» فَقَالَ بِأَبِي أَنْتَ وَأُمِّي يَا رَسُولَ اللهِ إِنِّي أَجِدُنِي قَوِيًّا فَقَالَ رَسُولُ اللهِ ﷺ «إِنِّي أَجِدُنِي قَوِيًّا إِنِّي أَجِدُنِي قَوِيًّا» فَمَا كَادَ أَنْ يَزِيدَهُ فَلَمَّا أَلَحَّ عَلَيْهِ قَالَ رَسُولُ ﷺ «صُمْ ثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ»