The Messenger of Allah ﷺ taught me tashahhud taking my hand within his palms, in the same way as he taught me a Sura of the Qur'an, and he narrated it as narrated above.
سَمِعْتُ ابْنَ مَسْعُودٍ يَقُولُ عَلَّمَنِي رَسُولُ اللَّهِ ﷺ التَّشَهُّدَ كَفِّي بَيْنَ كَفَّيْهِ كَمَا يُعَلِّمُنِي السُّورَةَ مِنَ الْقُرْآنِ وَاقْتَصَّ التَّشَهُّدَ بِمِثْلِ مَا اقْتَصُّوا