Sahih Bukhari · Hadith 4216

حدثنا قبيصة، حدثنا سفيان، عن طارق، قال ذكرت عند سعيد بن المسيب الشجرة فضحك فقال أخبرني أبي وكان، شهدها‏.‏

Narrated Tariq: (The tree where the Ridwan Pledge of allegiance was taken by the Prophet) was mentioned before Sa`id bin Al-Musaiyab. On that he smiled and said, "My father informed me (about it) and he had witnessed it (i.e. the Pledge) ."

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).