(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 Messenger (ﷺ) announced, "Allah's Messenger (ﷺ) forbids you to eat donkey's meat."
Sahih al-Bukhari Book 64, Hadith 215
← Previous Hadith regarding Allah's Statement: "Verily! We have granted you (O, Muhammad) Manifest victory." (48.1) It refers to the Al-Hudaibiya Pledge. And the companions of the Prophet (ﷺ) said (to the Prophet), "Congratulations and happiness for you; but what reward shall we get?" So Allah revealed:-- "That He may admit the believing men and women to gardens beneath which rivers flow." (48.5)

Sahih al-Bukhari Book 64, Hadith 214 Next Hadith → 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.

Sahih al-Bukhari Book 64, Hadith 216