The Messenger of Allah( may peace be upon him) used to teach us the tashahhud as he would teach us the Qur’an, and would say: The blessed adoration of the tongue, acts of worship (and) all good things are due to Allah. Peace be upon you, O Prophet, and Allah’s mercy and His blessings. Peace be upon us and upon Allah’s upright servants. I testify that there is no god but Allah, and I testify that Muhammad is Allah’s apostle (peace be upon him). (Using translation from Abū Dāʾūd 974)
إِنَّ رَسُولَ اللهِ ﷺ عُلِّمَ فَوَاتِحَ الْخَيْرِ وَجَوَامِعَهُ أَوْ جَوَامِعَ الْخَيْرِ وَفَوَاتِحَهُ وَإِنَّا كُنَّا لَا نَدْرِي مَا نَقُولُ فِي صَلَاتِنَا حَتَّى عُلِّمْنَا فَقَالَ قُولُوا التَّحِيَّاتُ لِلَّهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ السَّلَامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللهِ وَبَرَكَاتُهُ السَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللهِ الصَّالِحِينَ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللهُ وَأَشْهَدُأَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ