Tawus reported: We asked Ibn Abbas, may Allah be pleased with him, about sitting on the two feet in prayer and he said, “It is the Sunnah.” We said to him, “We see it as difficult for a man to do.” Ibn Abbas said, “Rather, it is the Sunnah of your Prophet, peace and blessings be upon him.”
Source: Ṣaḥīḥ Muslim 536
Grade: Sahih (authentic) according to Muslim
Al-Nawawi said, “It is related from Al-Shafi’i, may Allah be pleased with him, in Al-Buwayti and Al-Imla’ that it is recommended to sit in this manner between the two prostrations… As for sitting in the first tashahhud and in the rest, the Sunnah of both is to have the right foot propped up and sitting on the left foot (al-iftirash). And in the sitting of the final tashahhud, the Sunnah is to have the right foot propped up and the left foot tucked under (al-tawarruk).”
Source: Sharḥ al-Nawawī ‘alá Ṣaḥīḥ Muslim 536
عن طاوس قُلْنَا لِابْنِ عَبَّاسٍ فِي الْإِقْعَاءِ عَلَى الْقَدَمَيْنِ فَقَالَ هِيَ السُّنَّةُ فَقُلْنَا لَهُ إِنَّا لَنَرَاهُ جَفَاءً بِالرَّجُلِ فَقَالَ ابْنُ عَبَّاسٍ بَلْ هِيَ سُنَّةُ نَبِيِّكَ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ
536 صحيح مسلم كتاب المساجد ومواضع الصلاة باب جواز الإقعاء على العقبين
قال النووي وَقَدْ نَصَّ الشَّافِعِيُّ رَضِيَ اللَّهُ عَنْهُ فِي الْبُوَيْطِيِّ وَالْإِمْلَاءِ عَلَى اسْتِحْبَابِهِ فِي الْجُلُوسِ بَيْنَ السَّجْدَتَيْنِ … وَأَمَّا جِلْسَةُ التَّشَهُّدِ الْأَوَّلِ وَجِلْسَةُ الِاسْتِرَاحَةِ فَسُنَّتُهُمَا الِافْتِرَاشُ وَجِلْسَةُ التَّشَهُّدِ الْأَخِيرِ السُّنَّةُ فِيهِ التَّوَرُّكُ
536 شرح النووي على مسلم