Imam Ridha (peace be upon him) is the eighth divine light after the Holy Prophet (peace be upon him and his pure progeny). He administered the affairs of Muslims and the Shias in particular guiding them through the various difficult situations. The apparent caliphs disregarded the Imam's position and tried their best to underestimate them.
Al-Ma’mun, one of the caliphs during the time of the Imam would invite high-level scholars of different schools and thought to debate with the Imam thereby wanting to ruin the belief of the Shias in divine knowledge of the Imam. However, the Imam would always triumph and the debater(s) would become the follower of the Imam.
Imams’ popularity was more than that of Ma’mun. On one Eid, Ma’mun ordered the Imam to lead the Eid prayers to show that his apparent humbleness and friendship with the Imam. The Imam said that he would lead the prayers the way the prophet would the prayers. The people anticipated the Imam to come the way the preceding caliphs did but, to everyone’s surprise, the Imam came bare-footed while reciting the Takbir. The commanders who had come to this event with their official uniforms quickly got off their horses and took off their shoes and walked after Imam while they were saying Takbir. People cried out of humility. When Ma’mun was informed about the events he scared for his caliphate and quickly sent for the Imam. Eventually, fearing for his position, Ma’mun poisoned the Imam and martyred him.
We ask Allah to hasten the reappearance of the Imam and to bless us with the visitation of Imam al-Ridha (peace be upon him)