Narrated Zahir Al-Aslami:
(who was one of those who had witnessed (the Pledge of allegiance beneath) the Tree) While I was making fire beneath the cooking pots containing donkey's meat, the announcer of Allah's Apostle announced, "Allah's Apostle forbids you to eat donkey's meat." 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.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، حَدَّثَنَا أَبُو عَامِرٍ، حَدَّثَنَا إِسْرَائِيلُ، عَنْ مَجْزَأَةَ بْنِ زَاهِرٍ الأَسْلَمِيِّ، عَنْ أَبِيهِ ـ وَكَانَ مِمَّنْ شَهِدَ الشَّجَرَةَ ـ قَالَ إِنِّي لأُوقِدُ تَحْتَ الْقِدْرِ بِلُحُومِ الْحُمُرِ إِذْ نَادَى مُنَادِي رَسُولِ اللَّهِ صلى الله عليه وسلم إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم يَنْهَاكُمْ عَنْ لُحُومِ الْحُمُرِ.
Sahih al-Bukhari, 4174
Sahih al-Bukhari, Vol. 5, Book of Military Expeditions led by the Prophet ﷺ (Maghaazi), Hadith 491
Sahih al-Bukhari, Book of Military Expeditions led by the Prophet ﷺ (Maghaazi), Hadith 491