when we (prayed and) sat up during prayer along the Messenger of Allah (may peach be upon him), we said: “Peace be to Allah before it is supplicated for His servants; peace be to so and so. “The Messenger of Allah ﷺ said: Do not say “Peace be to Allah ,”for Allah Himself is peace. When one of you sits(during the prayer), he should say: The adoration of the tongue are due to Allah, and acts of worship and all good things. Peace be upon you, O Prophet, and Allah’s mercy and His blessings. Peace be upon us and upon Allah’s upright servants. When you say that, it reaches every upright servant in heavens and earth or between heavens and earth. I testify that there is no god but Allah, and I testify that Muhammad is His servant and apostle. Then he may choose any supplication which pleases him and offer it. (Using translation from Abū Dāʾūd 968)   

كُنَّا إِذَا صَلَّيْنَا خَلْفَ رَسُولِ اللَّهِ ﷺ قُلْنَا السَّلَامُ عَلَى اللَّهِ قَبْلَ عِبَادِهِ السَّلَامُ عَلَى جِبْرِيلَ السَّلَامُ عَلَى مِيكَائِيلَ السَّلَامُ عَلَى إِسْرَافِيلَ السَّلَامُ عَلَى فُلَانٍ وَفُلَانٍ قَالَ فَأَقْبَلَ عَلَيْنَا رَسُولُ اللَّهِ ﷺ فَقَالَ إِنَّ اللَّهَ تَعَالَى هُوَ السَّلَامُ فَإِذَا جَلَسْتُمْ فِي الصَّلَاةِ فَقُولُوا التَّحِيَّاتُ لِلَّهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ السَّلَامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ السَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ فَإِنَّكُمْ إِذَا قُلْتُمُوهَا أَصَابَتْ كُلَّ عَبْدٍ صَالِحٍ فِي السَّمَاءِ وَالْأَرْضِ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ ثُمَّ لِيَتَخَيَّرْ مَا شَاءَ  

[Machine] "And indeed, the Messenger of Allah ﷺ took the hand of Abdullah and taught him the Tashahhud in prayer, which is: 'All greetings, prayers, and good deeds are for Allah. Peace be upon you, O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous servants of Allah.' Zuhayr said, 'I think he said: I bear witness that there is no god but Allah and I bear witness that Muhammad is His servant and His Messenger.' He hesitated in these two statements; if you do this or finish it, then you have completed your prayer. If you wish to stand, then stand, and if you wish to sit, then sit."  

وَأَنَّ رَسُولَ اللَّهِ ﷺ أَخَذَ بِيَدِ عَبْدِ اللَّهِ فَعَلَّمَهُ التَّشَهُّدَ فِي الصَّلَاةِ «التَّحِيَّاتُ لِلَّهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ السَّلَامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ السَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ» قَالَ زُهَيْرٌ أُرَاهُ قَالَ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ أَيْضًا شَكَّ فِي هَاتَيْنِ الْكَلِمَتَيْنِ إِذَا فَعَلْتَ هَذَا أَوْ قَضَيْتَ فَقَدْ قَضَيْتَ صَلَاتَكَ إِنْ شِئْتَ أَنْ تَقُومَ فَقُمْ وَإِنْ شِئْتَ أَنْ تَقْعُدَ فَاقْعُدْ