The Book of Occultation — al-Ṭūsī · Hadith 523 (#Ḥadīth #6)

299- وروي عن موسى بن بكر قال: كنت في خدمة أبي الحسن عليه السلام فلم أكن أرى شيئا يصل إليه إلا من ناحية المفضل، ولربما رأيت الرجل يجئ بالشيء فلا يقبله منه ويقول: أوصله إلى المفضل.

H 299 - It is narrated from Musa bin Bakr that he said: I was in the company of Imam Musa Kadhim and I never saw anything being brought for the Imam, but that it came to Mufaddal and many a times saw people bring something that the Imam did not accept; on the contrary he said: Deliver it to Mufaddal.

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