Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
muslim:411b[Chain 1] Qutaybah b. Saʿīd > Layth [Chain 2] Muḥammad b. Rumḥ > al-Layth > Ibn Shihāb > Anas b. Mālik

The Messenger of Allah ﷺ fell down from a horse and he was grazed and he led the prayer for us sitting, and the rest of the hadith is the same.  

مسلم:٤١١bحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ حَدَّثَنَا لَيْثٌ ح وَحَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ أَخْبَرَنَا اللَّيْثُ عَنِ ابْنِ شِهَابٍ عَنْ أَنَسِ بْنِ مَالِكٍ قَالَ

خَرَّ رَسُولُ اللَّهِ ﷺ عَنْ فَرَسٍ فَجُحِشَ فَصَلَّى لَنَا قَاعِدًا ثُمَّ ذَكَرَ نَحْوَهُ