It was narrated that Aishah said:"I never saw the Messenger of Allah (ﷺ) pray sitting down until he grew old. Then he would pray sitting down and when there were thirty or forty verses left, he would stand up and recite them, then bow."
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا عِيسَى بْنُ يُونُسَ، قَالَ حَدَّثَنَا هِشَامُ بْنُ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ مَا رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم صَلَّى جَالِسًا حَتَّى دَخَلَ فِي السِّنِّ فَكَانَ يُصَلِّي وَهُوَ جَالِسٌ يَقْرَأُ فَإِذَا غَبَرَ مِنَ السُّورَةِ ثَلاَثُونَ أَوْ أَرْبَعُونَ آيَةً قَامَ فَقَرَأَ بِهَا ثُمَّ رَكَعَ .
Nesai
The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day • Hadith 1649