[Machine] Ibn Abbas sent to Umm Salama and Aisha inquiring about the days that the Messenger of Allah ﷺ used to prefer fasting. They replied, "The Messenger of Allah ﷺ used to fast most frequently on Saturdays and Sundays, saying, 'These are the days of celebration for the People of the Book, and we like to differ from them.'"  

أَنَّ ابْنَ عَبَّاسٍ بَعَثَ إِلَى أُمِّ سَلَمَةَ وَإِلَى عَائِشَةَ يَسْأَلُهُمَا مَا كَانَ رَسُولُ اللهِ ﷺ يُحِبُّ أَنْ يَصُومَ مِنَ الْأَيَّامِ فَقَالَتَا مَا مَاتَ رَسُولُ اللهِ ﷺ حَتَّى كَانَ أَكْثَرُ صَوْمِهِ يَوْمَ السَّبْتِ وَالْأَحَدِ وَيَقُولُ «هُمَا عِيدَانِ لِأَهْلِ الْكِتَابِ فَنَحْنُ نُحِبُّ أَنْ نُخَالِفَهُمْ»  

[Machine] Ibn Abbas and some of the Prophet's companions sent me to Umm Salamah and asked, "Which days did the Prophet ﷺ fast the most?" She replied, "He used to fast on Saturdays and Sundays." They criticized me and thought that I didn't remember correctly, so they sent me away. Umm Salamah repeated the same answer to them, and I informed them. They all got up and said, "We sent you to her, and she claimed that you said this and that." Umm Salamah replied, "She is telling the truth. The Messenger of Allah ﷺ used to fast on Saturdays and Sundays more than any other days, and he used to say, 'Those are days of celebration for the disbelievers, so I prefer to differ from them.'"  

أَرْسَلَنِي ابْنُ عَبَّاسٍ وَنَاسٌ مِنْ أَصْحَابِ النَّبِيِّ ﷺ إِلَى أُمِّ سَلَمَةَ أَيُّ الْأَيَّامِ كَانَ النَّبِيُّ ﷺ أَكْثَرَهَا صِيَامًا؟ قَالَتْ يَوْمُ السَّبْتِ وَالْأَحَدِ فَأَنْكَرُوا عَلَيَّ وَظَنُّوا أَنِّي لَمْ أَحْفَظْ فَرَدُّونِي فَقَالَتْ مِثْلَ ذَلِكَ فَأَخْبَرْتُهُمْ فَقَامُوا بِأَجْمَعِهِمْ فَقَالُوا إِنَّا أَرْسَلْنَا إِلَيْكِ فِي كَذَا وَكَذَا فَزَعَمَ هَذَا أَنَّكِ قُلْتِ كَذَا وَكَذَا قَالَتْ صَدَقَ كَانَ رَسُولُ اللهِ ﷺ يَصُومُ يَوْمَ السَّبْتِ وَالْأَحَدِ أَكْثَرَ مَا يَصُومُ مِنَ الْأَيَّامِ وَيَقُولُ إِنَّهُمَا يَوْمَا عِيدٍ لِلْمُشْرِكِينَ فَأَنَا أُحِبُّ أَنْ أُخَالِفَهُمْ