Sahih al-Bukhari #4174 · Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)

Sahih al-Bukhari
Sahih al-Bukhari · Book 64 · Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Sahih al-Bukhari · كتاب 64 · كتاب المغازي
The same narration was told by Majzaa from a man called Uhban bin Aus who was one of those who had witnessed (the Pledge of allegiance beneath) the Tree., and who had some trouble in his knee so that while doing prostrations, he used to put a pillow underneath his knee
وَعَنْ مَجْزَأَةَ، عَنْ رَجُلٍ، مِنْهُمْ مِنْ أَصْحَابِ الشَّجَرَةِ اسْمُهُ أُهْبَانُ بْنُ أَوْسٍ وَكَانَ اشْتَكَى رُكْبَتَهُ، وَكَانَ إِذَا سَجَدَ جَعَلَ تَحْتَ رُكْبَتِهِ وِسَادَةً‏.‏
Reference : Sahih al-Bukhari 4174In-book reference : Book 64, Hadith 216