"The Messenger of Allah used to fast three days in the middle of every month, and he rarely did not fast on Friday."  

كَانَ رَسُولُ اللَّهِ ﷺ يَصُومُ ثَلاَثَةَ أَيَّامٍ مِنْ غُرَّةِ كُلِّ شَهْرٍ وَقَلَّمَا يُفْطِرُ يَوْمَ الْجُمُعَةِ  

" I heard the Messenger of Allah say: 'The month of patience ( Ramadan) and three days of each month is fasting for a lifetime."' (Sahih).  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ شَهْرُ الصَّبْرِ وَثَلاَثَةُ أَيَّامٍ مِنْ كُلِّ شَهْرٍ صَوْمُ الدَّهْرِ  

"I heard the Messenger of Allah say: 'It is a good fast to fast three days of each month".  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ صِيَامٌ حَسَنٌ ثَلاَثَةُ أَيَّامٍ مِنَ الشَّهْرِ  

"I heard Ibn 'Umar say" "The Prophet used to fast three days of each month.  

سَمِعْتُ ابْنَ عُمَرَ يَقُولُ كَانَ النَّبِيُّ ﷺ يَصُومُ ثَلاَثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ  

The Messenger of Allah ﷺ used to fast three days every month.  

كَانَ رَسُولُ اللَّهِ ﷺ يَصُومُ يَعْنِي مِنْ غُرَّةِ كُلِّ شَهْرٍ ثَلاَثَةَ أَيَّامٍ  

[Machine] I heard Ibn Umar say, "The Prophet ﷺ used to fast three days every month: on the first Thursday, the Monday that follows, and the Monday that follows."  

سَمِعْتُ ابْنَ عُمَرَ يَقُولُ كَانَ النَّبِيُّ ﷺ يَصُومُ ثَلَاثَةَ أَيَّامٍ مِنْ كُلِّ شَهْرٍ الْخَمِيسَ مِنْ أَوَّلِ الشَّهْرِ وَالِاثْنَيْنِ الَّذِي يَلِيهِ وَالِاثْنَيْنِ الَّذِي يَلِيهِ  

" I heard the Messenger of Allah say: 'The month of patience ( Ramadan) and three days of each month is fasting for a lifetime."' (Sahih). (Using translation from Nasāʾī 2408)  

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ صَوْمُ شَهْرِ الصَّبْرِ وَثَلَاثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ صَوْمُ الدَّهْرِ  

The Messenger of Allah ﷺ used to fast three days every month. (Using translation from Abū Dāʾūd 2450)   

أَنَّ رَسُولَ اللهِ ﷺ كَانَ يَصُومُ ثَلَاثَةَ أَيَّامٍ مِنْ غُرَّةِ كُلِّ شَهْرٍ