‘Abdallah b. Mas'ud said that in the first two <i>rak'as</i> the Prophet (ﷺ) was as though he were on heated stones till he got up.* *A figurative phrase to express the shortening of the sitting during the <i>tashahhud</i>. Tirmidhi, Abu Dawud and Nasa’i transmitted it.

وَعَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ قَالَ: كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي الرَّكْعَتَيْنِ الْأُولَيَيْنِ كَأَنَّهُ عَلَى الرَّضْفِ حَتَّى يَقُومَ. رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَالنَّسَائِيُّ