Tashahhud (Sitting for the Testimony):
Again, when the Prophet (may Allah bless him and give him peace) finished the second rak‘ah, he would sit for the tashahhud. If it was a two-rak‘ah prayer like Fajr, he would spread out his left leg and sit upon it, just as he sat between the two prostrations (this sitting posture is called iftirāsh). In the first tashahhud of three- or four-rak‘ah prayers, he would also sit in the same manner.
حَدَّثَنَا مَحْمُودُ بْنُ غَيْلَانَ، وَيَحْيَى بْنُ مُوسَى، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنْ مَعْمَرٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عُمَرَ، عَنْ نَافِعٍ، عَنْ ابْنِ عُمَرَ، أَنّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ إِذَا جَلَسَ فِي الصَّلَاةِ وَضَعَ يَدَهُ الْيُمْنَى عَلَى رُكْبَتِهِ وَرَفَعَ إِصْبَعَهُ الَّتِي تَلِي الْإِبْهَامَ الْيُمْنَى يَدْعُو بِهَا وَيَدُهُ الْيُسْرَى عَلَى رُكْبَتِهِ بَاسِطَهَا عَلَيْهِ قَالَ:‏‏‏‏ وَفِي الْبَاب عَنْ عَبْدِ اللَّهِ بْنِ الزُّبَيْرِ،‏‏‏‏ وَنُمَيْرٍ الْخُزَاعِيِّ، ‏‏‏‏‏‏وَأَبِي هُرَيْرَةَ، ‏‏‏‏‏‏وَأَبِي حُمَيْدٍ،‏‏‏‏ وَوَائِلِ بْنِ حُجْرٍ، ‏‏‏‏‏‏قَالَ أَبُو عِيسَى:‏‏‏‏ حَدِيثُ ابْنِ عُمَرَ حَدِيثٌ حَسَنٌ غَرِيبٌ، ‏‏‏‏‏‏لَا نَعْرِفُهُ مِنْ حَدِيثِ عُبَيْدِ اللَّهِ بْنِ عُمَرَ إِلَّا مِنْ هَذَا الْوَجْهِ، ‏‏‏‏‏‏وَالْعَمَلُ عَلَيْهِ عِنْدَ بَعْضِ أَهْلِ الْعِلْمِ مِنْ أَصْحَابِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَالتَّابِعِينَ يَخْتَارُونَ الْإِشَارَةَ فِي التَّشَهُّدِ، ‏‏‏‏‏‏وَهُوَ قَوْلُ أَصْحَابِنَا.
Narrated by Mahmood ibn Ghailan and Yahya ibn Musa:
They said, ‘Abd al-Razzaq narrated to us, from Ma‘mar, from ‘Ubaydullah ibn ‘Umar, from Nafi‘, from Ibn ‘Umar (may Allah be pleased with them), that the Prophet (may Allah bless him and give him peace), when he sat in prayer, would place his right hand on his right knee and raise the finger next to the thumb, supplicating with it, and his left hand would be placed flat on his left knee.’
Abu ‘Isa (al-Tirmidhi) said: In this topic, there are also narrations from ‘Abdullah ibn al-Zubayr, Numayr al-Khuza‘i, Abu Hurayrah, Abu Humayd, and Wa’il ibn Hujr.
Abu ‘Isa said: The hadith of Ibn ‘Umar is hasan gharib (good but singular in chain), and we do not know it from ‘Ubaydullah ibn ‘Umar except through this narration.
The practice upon this (raising the finger in tashahhud) is followed by some of the scholars among the Companions of the Prophet (may Allah bless him and give him peace) and the Successors, and this is also the view of our companions.
(Sunan al-Tirmidhi, Hadith 294; Sahih Muslim, Hadith 580)