I asked our Shaykh Muhammad ibn al-Hasan ibn al-Walid about what the common people practice of saying 'La ilaha illa Allah سبحانه وتعالى' (the testimony of faith) and 'Allahu Akbar' (God is Greatest) after the Jumu’ah prayer—what is it? He said: It has been narrated that the Umayyads used to curse The Commander of the Faithful (Imam Ali عليه السلام) after the Jumu’ah prayer three times. When Umar ibn Abdul Aziz assumed power, he forbade that practice and said to the people: Declaring 'La ilaha illa Allah سبحانه وتعالى' and 'Allahu Akbar' after the prayer is better.