Imam Sadiq (a.s) said: “Whoever opposes a tradition is an infidel.”
عن أبي عبد الله (عليه السلام) قال
من خالف سنة فقد كفر.
Similar narrations
Mishkāt al-Anwār #791“Whoever opposes the tradition of Muhammad (the Prophet) is an infidel.”
Al-Kāfi #207“Abu ‘Abdallah (a.s.) who has said, ‘Whoever disagrees with the book of Allah and the Sunnah of Prophet Muhammad (s.a.) he has certainly...