Sunan an-Nasai Book 12, Hadith 1175

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا الْمُعْتَمِرُ، قَالَ سَمِعْتُ أَيْمَنَ، - وَهُوَ ابْنُ نَابِلٍ - يَقُولُ حَدَّثَنِي أَبُو الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُعَلِّمُنَا التَّشَهُّدَ كَمَا يُعَلِّمُنَا السُّورَةَ مِنَ الْقُرْآنِ ‏ "‏ بِسْمِ اللَّهِ وَبِاللَّهِ التَّحِيَّاتُ لِلَّهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ السَّلاَمُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ السَّلاَمُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ أَسْأَلُ اللَّهَ الْجَنَّةَ وَأَعُوذُ بِاللَّهِ مِنَ النَّارِ ‏"‏ ‏.‏

It was narrated that Jabir said:"The Messenger of Allah (ﷺ) used to teach us the tashahhud just as he would teach us a surah of the Quran: "Bismillah, wa billahi. At-tahiyyatu lillahi was-salawatu wat-tayyibat, as-salamu 'alaika ayyuhan-Nabiyyu wa rahmatAllahi wa baraktuhu. As-salamu 'alaina wa 'ala 'ibad illahis-salihin, ashahdu an la illaha ill-Allah wa ashhadu anna Muhammadan 'abduhu wa rasuluhu. A'sal Allahal-jannah wa a'udhu Billahi min an-nar (Allah compliments, prayers and pure words are due to Allah. Peace be upon you, O Prophet, and the mercy of Allah (SWT) and his blessings. Peace be upon us and upon the righteous slaves of Allah (SWT). I bear witness that none has the right to be worshipped except Allah and I bear witness that Muhammad is His slave and Messenger. I ask Allah for Paradise and I seek refuge with Allah from the Fire