1. Muhammad ibn Yahya has narrated from Ahmad and ‘Abdallah (both) sons of Muhammad ibn ‘Isa from Ali ibn al-Hakam from Sayf ibn ‘Umayra from Mufaddal ibn Yazid that Abu ‘Abdillah (al-Sadiq) عليه السلام said: "I would like to warn you about two forms of behavior that lead a man to destruction. I prohibit you from dealing with Allah on the basis of falsehood and from giving fatwa to people without knowledge.”