Imam al-Raza (A.S.) had inherited great qualities from his ancestors. He was a versatile person and had full command over many languages. Ibn ul-Atheer al-Jazari rightly said that Imam al-Raza (A.S.) was undoubtedly the greatest sage, saint and scholar of the second century (AH).

On his way to Marv and accompanied by the soldiers of al-Mamoon, Imam al-Raza (A.S.) arrived at a place called Naishabour. Thousands of faithful gathered to welcome him. Abu Dhar’ah al-Razi and Muhammad ibn Aslam al-Toosi, the two great scholars of the day were also in the crowd. They stepped out and requested the Imam (A.S.) to address the gathering. The Imam (A.S.) granted the request and in his brief address informed the huge gathering about the real interpretation of Laa ilaaha illallah (There is no god but Allah). He (A.S.) said,
“ I have heard my father Musa ibn Ja’far (A.S.) saying that he heard from his father Ja’far ibn Muhammad (A.S.) saying that he heard his father Muhammad ibn Ali (A.S.) saying that he heard from his father Ali ibn al-Husain (A.S.) saying that he heard from his father al-Husain ibn Ali (A.S.) saying that he heard from his father Ali ibn Abi Talib (A.S.) saying that he heard from the Holy Prophet (pbuh) saying that he heard from Jibrael saying that Allah told him: ‘The kalima (Laa ilaaha illallah) is My fortress, whoever says it enters My fortress, and whoever enters My fortress shall be safe from My punishment’”.
The Imam (A.S.) then paused for a moment and continued,
“There are few conditions to entitle the entrance to the fortress and I am one of its conditions”. (Ahsan al-Maqaal)

What the Imam (A.S.) was implying is that the greatest of all conditions was sincere and complete submission to the Imam of the day. He (A.S.) then very boldly and frankly explained to the people that any disloyalty to the Holy Prophet (pbuh) and his descendants would withdraw the right of the entrance to the fortress. The only way to earn the pleasure of Allah (SWT) was to obey the Prophet (pbuh) and his progeny and that was the only path to salvation and immortality.

Article from The Official Website Of Grand Ayatollah Saafi Gulpaygani