al-Hasan ibn al-Jahm transmitted from al-Ridha (peace be upon him), I said:“Contradictory sayings from you reach us.” He (peace be upon him) said: “Whatever reaches you from us, compare it with the Book of God and with our sayings, if they agree with both, it is from us, and if it does not agree with both, it is not from us.” [al-`Ashrat al-Kamilah fi l-Ijtihad wa l-Taqlid, page 135]