“The Messenger of Allah ﷺ fell ill and some of his Companions came to visit him. The Messenger of Allah ﷺ performed prayer while sitting down, and they prayed behind him standing up. He gestured them to sit down, and when he finished he said: ‘The Imam is appointed to be followed. When he bows, then bow; when he stands up again, then stand up, and if he prays sitting down then pray sitting down.’” (Using translation from Ibn Mājah 1237)
اشْتَكَى رَسُولُ اللهِ ﷺ فَدَخَلَ عَلَيْهِ نَاسٌ مِنْ أَصْحَابِهِ يَعُودُونَهُ فَصَلَّى رَسُولُ اللهِ ﷺ جَالِسًا فَصَلَّوْا بِصَلَاتِهِ قِيَامًا فَأَشَارَ إِلَيْهِمْ أَنِ اجْلِسُوا فَجَلَسُوا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا