Messenger of Allah ﷺ rode a horse and fell down and the right side of his body was injured. On that day he prayed one of the prayers sitting and we also prayed behind him sitting. When the Prophet ﷺ finished the prayer with Taslim, he said, "The Imam is to be followed and if he prays standing then pray standing, and bow when he bows, and raise your heads when he raises his head; prostrate when he prostrates; and if he says "Samiʿa l-lahu liman hamidah", you should say, "Rabbana wa laka l-hamd.:  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَجُحِشَ شِقُّهُ الأَيْمَنُ قَالَ أَنَسٌ ؓ فَصَلَّى لَنَا يَوْمَئِذٍ صَلاَةً مِنَ الصَّلَوَاتِ وَهْوَ قَاعِدٌ فَصَلَّيْنَا وَرَاءَهُ قُعُودًا ثُمَّ قَالَ لَمَّا سَلَّمَ إِنَّمَا جُعِلَ الإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا سَجَدَ فَاسْجُدُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ  

"The Imam is appointed to be followed. If he prays standing then pray standing; when he bows, bow; when he says, Sami' Allahu liman hamidah (Allah hears those who praise Him), say 'Rabbana lakalhamd (Our Lord, to You be praise); and if he prays sitting then pray sitting, all of you."  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الأَيْمَنُ فَصَلَّى صَلاَةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ فَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا لَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا أَجْمَعُونَ  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting.  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الأَيْمَنُ فَصَلَّى صَلاَةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ وَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا أَجْمَعُونَ  

Yahya related to me from Malik from Ibn Shihab from Anas ibn Malik that the Messenger of Allah ﷺ fell off his horse when riding, and his right side was scraped, so he did one of the prayers sitting, and we prayed behind him sitting. When he left, he said, "The imam is appointed to be followed. If he prays standing, then pray standing, and when he goes into ruku, go into ruku, and when he rises, rise, and when he says, 'Allah hears whoever praises him,' say, 'Our Lord, praise belongs to You,' and if he prays sitting, then all of you pray sitting."  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ فَجُحِشَ شِقُّهُ الأَيْمَنُ فَصَلَّى صَلاَةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ وَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا أَجْمَعُونَ  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting. (Using translation from Abū Dāʾūd 601)  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الْأَيْمَنُ فَصَلَّى صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ جَالِسٌ فَصَلَّيْنَا مَعَهُ جُلُوسًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَلَا تَخْتَلِفُوا عَلَيْهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِنْ صَلَّى قَاعِدًا فَصَلُّوا قُعُودًا أَجْمَعُونَ  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting. (Using translation from Abū Dāʾūd 601)  

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ يَعْنِي فَجُحِشَ شِقُّهُ الْأَيْمَنُ فَصَلَّى صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ فَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ «إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا أَجْمَعُونَ»  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting. (Using translation from Abū Dāʾūd 601)   

أَنَّ رَسُولَ اللَّهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الْأَيْمَنُ قَالَ أَنَسٌ فَصَلَّى لَنَا يَوْمَئِذٍ صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ فَصَلَّيْنَا وَرَاءَهُ قُعُودًا ثُمَّ قَالَ حِينَ سَلَّمَ «إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى الْإِمَامُ قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا سَجَدَ فَاسْجُدُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى قَاعِدًا فَصَلُّوا قُعُودًا أَجْمَعُونَ»  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting. (Using translation from Abū Dāʾūd 601)  

أَنَّ رَسُولَ اللهِ ﷺ رَكَبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الْأَيْمَنُ فَصَلَّى صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ وَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلَّوْا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا قَالَ سَمِعَ اللهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلَّوْا جُلُوسًا أَجْمَعُونَ  

the Imam is appointed only to be followed ; so when he prays standing, pray standing, and when he bows, bow; when he raises himself, raise yourselves; when he says “Allah listen to him who praises Him”, “Our Lord ! to Thee be the praise”: and when he prays sitting all of you pray sitting. (Using translation from Abū Dāʾūd 601)   

أَنَّ رَسُولَ اللهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الْأَيْمَنُ فَصَلَّى صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ قَاعِدٌ فَصَلَّيْنَا وَرَاءَهُ قُعُودًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا رَفَعَ فَارْفَعُوا وَإِذَا قَالَ سَمِعَ اللهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا صَلَّى جَالِسًا فَصَلُّوا جُلُوسًا أَجْمَعِينَ أَخْرَجَاهُ فِي الصَّحِيحِ مِنْ حَدِيثِ مَالِكٍ  

[Machine] That the Messenger of Allah ﷺ rode a horse, and it stumbled and injured its right side. He then performed a prayer for us, while sitting, and we prayed with him while sitting. When he finished, he said: "Verily, the imam has been appointed to be followed, so do not differ from him. When he prays standing, then pray standing, and when he says 'Allahu Akbar', then say 'Allahu Akbar', and when he says 'Sami Allahu liman hamidah', then say 'Rabbana wa lakal hamd', and when he prostrates, then prostrate, and when he prays sitting, then pray sitting, all together." This is an authentic narration in Sahihain from the hadith of Malik and others, narrated by Muslim from Hirmalah from Ibn Wahb, and likewise.  

أَنَّ رَسُولَ اللهِ ﷺ رَكِبَ فَرَسًا فَصُرِعَ عَنْهُ فَجُحِشَ شِقُّهُ الْأَيْمَنُ فَصَلَّى لَنَا صَلَاةً مِنَ الصَّلَوَاتِ وَهُوَ جَالِسٌ فَصَلَّيْنَا مَعَهُ جُلُوسًا فَلَمَّا انْصَرَفَ قَالَ إِنَّمَا جُعِلَ الْإِمَامُ لِيُؤْتَمَّ بِهِ فَلَا تَخْتَلِفُوا عَلَيْهِ فَإِذَا صَلَّى قَائِمًا فَصَلُّوا قِيَامًا وَإِذَا كَبَّرَ فَكَبِّرُوا وَإِذَا قَالَ سَمِعَ اللهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا وَلَكَ الْحَمْدُ وَإِذَا سَجَدَ فَاسْجُدُوا وَإِذَا صَلَّى قَاعِدًا فَصَلُّوا قُعُودًا أَجْمَعِينَ مَخَرَّجٌ فِي الصَّحِيحَيْنِ مِنْ حَدِيثِ مَالِكٍ وَغَيْرِهِ وَرَوَاهُ مُسْلِمٌ عَنْ حَرْمَلَةَ عَنِ ابْنِ وَهْبٍ وَكَذَلِكَ