Sahih al-Bukhari 4174
Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · Hadith 216
Hadith text
وَعَنْ مَجْزَأَةَ، عَنْ رَجُلٍ، مِنْهُمْ مِنْ أَصْحَابِ الشَّجَرَةِ اسْمُهُ أُهْبَانُ بْنُ أَوْسٍ وَكَانَ اشْتَكَى رُكْبَتَهُ، وَكَانَ إِذَا سَجَدَ جَعَلَ تَحْتَ رُكْبَتِهِ وِسَادَةً.
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
(yehi riwaayat Majzaa ne ek shaks se sunaee jinka naam Uhban bin Aus tha, jo un logon mein se ek the jinhone darakht ke neeche (Bai'at) dekhi thi, aur jinke ghutne mein kuch takleef thi, isliye sajda karte waqt, woh apne ghutne ke neeche ek takiya rakhte the.)
Sahih al-Bukhari 4174 · Book 64, Hadith 216
Read all hadith in Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)