[Machine] Four fasts that the Prophet Muhammad ﷺ never used to leave were the fasting of Ashura, the fasting of the tenth of Muharram, and three days of fasting every month.
أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ النَّبِيُّ ﷺ صِيَامُ عَاشُورَاءَ وَالْعَشْرُ وَثَلَاثَةُ أَيَّامٍ مِنْ كُلِّ شَهْرٍ
"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)."
أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ النَّبِيُّ ﷺ صِيَامَ عَاشُورَاءَ وَالْعَشْرَ وَثَلاَثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَرَكْعَتَيْنِ قَبْلَ الْغَدَاةِ
"The Prophet used to fast the ten (days), and three days of each month: Monday and Thursday."
عَنْ بَعْضِ أَزْوَاجِ النَّبِيِّ ﷺ قَالَتْ كَانَ النَّبِيُّ ﷺ يَصُومُ الْعَشْرَ وَثَلاَثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ الاِثْنَيْنِ وَالْخَمِيسَ
"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)." (Using translation from Nasāʾī 2416)
أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ النَّبِيُّ ﷺ صِيَامَ عَاشُورَاءَ وَالْعَشْرَ وَثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَالرَّكْعَتَيْنِ قَبْلَ الْغَدَاةِ
"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)." (Using translation from Nasāʾī 2416)
«أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ رَسُولُ اللَّهِ ﷺ صِيَامَ يَوْمِ عَاشُورَاءَ وَالْعَشْرَ وَثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَالرَّكْعَتَيْنِ قَبْلَ الْغَدَاةِ»
"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)." (Using translation from Nasāʾī 2416)
أَرْبَعٌ لَمْ يَكُنْ يَدَعُهُنَّ النَّبِيُّ ﷺ «صِيَامُ عَاشُورَاءَ وَالْعَشْرُ وَثَلَاثَةُ أَيَّامٍ مِنْ كُلِّ شَهْرٍ وَرَكْعَتَينِ قَبْلَ الْغَدَاةِ»