The infallible Imam was divinely entitled "al-Rida" which means that Allah Almighty and His holy messenger were deeply pleased with him.
Imam Khomeini, the late founder of the Islamic Republic said that Iranian feel pride that they are living under shelter of shrine of Imam Reza (PBUH). The holy site is center of knowledge, landing place of angels.
Imam Rida, one of the infallible successors of the holy prophet of Islam was decorated with numerous divine-oriented moral attributes and was well-known and popular among people due to his knowledge and wisdom.
Imam Musa Ibn Ja’far (PBUH) could foresee that the hostile Abbasid ruler would not allow him to live peacefully and circumstances would take such a turn that his followers would not be able to see him or enquire about his successor prior to his death.
So while free and undisturbed in Madinah he felt the need to introduce his successor to his followers. He, therefore, assembled seventeen prominent dignitaries from the descendants of Imam ‘Ali (PBUH) and proclaimed that his son ‘Ali Ibn Musa (as) would succeed him.
He also wrote his will on which 60 respected elders of Madinah signed as witnesses. Such elaborated arrangements were never made by any other Imam and they proved to be most appropriate due to the controversy about the Imamate which ensued after the death of Imam Musa Ibn Ja’far (as) .
Imam Ridha’ (as) was 35 years old when his father died in prison of Harun al-Rashid in Baghdad and the responsibilities of the Imamate devolved on him. At that time Harun Al-Rashid was the absolute ruler of Baghdad and the descendants of Imam ‘Ali (PBUH) were passing as ever, through trials and tribulations because of the tyranny of the Abbasid ruler.
Yet Imam Ridha’ (PBUH) carried on the responsibility of administering the Divine Law of Shari’ah as taught by the Holy Prophet and Imams of the Ahlul Bayt after him.
While Imam Ridha’ was with Mamun in Merv, his Prime Minister Fadl ibn Sahl arranged a conference on religions to which he invited the leaders of different sects, including Zoroastrians and Christians and Jews, that they might hear what the Imam of the Ahlul Bayt had to say to impress them of their spiritual abilities and excellences.
It was in these discussions with leaders of other faiths that the Imam clarified the position of sinlessness of the Prophets and of the guided Imams. These conferences were so successful that at one stage Mamun was fearful of the increasing influences of the Imam on the people as a whole.
In one such incidence on the occasion of the Eidul Fitr, the whole strategy of Mamun and the shear hypocrisy of the drama he was playing was exposed. He had asked the Imam to lead the Eidul Fitr prayers at the end of Ramadan that year. First the Imam declined, but when Mamun insisted, he agreed on the condition that he will direct the occasion as he would deem fit.
On the morning of the Eidul Fitr, when the military and civil leaders assembled outside the door of the Imam to come out and lead the prayers, they saw the Imam come out of the house bare foot, wearing a white shirt and white headgear. Imam also advised his companions to follow him in the same manner. He came out on the Road to the mosque outside the city of Merv.
All the citizens who saw the Imam in this fashion copied him and all walked barefoot. Even the military chiefs and civil judges walked bare foot. A huge crowd followed the Imam. He was saying Takbir loudly and all were following him and shouting Takbir (God is great).
The situation became so tense that when Mamun was informed of this huge following of the Imam he immediately sent a request to the Imam to withdraw from leading the Eid prayers. Imam withdrew and it was a great show down for the Emperor and exposed his trickery to the full.