27. My father said: Ahmad ibn Idris said; Muhammad ibn Ahmad said, on the authority of `Ali ibn Isma`il, on the authority of al-Mu`alla ibn Muhammad ibn al-Basri, on the authority of `Ali ibn Asbar, on the authority of Ja`far ibn Sama`ah, on the authority of more than one, on the authority of Zurarah that I asked Abu Ja`far al-Baqir : “What is the proof of Allah over the servants?” He answered, “They should only say what they know, and refrain from saying what they know not.”