Amongst the indications of the fact that Imam's martyrdom was carried out by Ma’mun is that the people gathered on the same day of the martyrdom and everyone believed that the Caliph had poisoned the Imam. The importance of the matter is because people present in Imam's living area, more than others had understood the situation and political conditions of the Imam and Ma’mun.
Some historians who believed in the poisoning of the Imam include: Ibn Hajar, Ibn Sabbagh Maliki, Mas‘udi, Qundusi Hanafi, Ibn TabaTaba, etc. Abdallah b. Musa, in a letter to Ma’mun that day, asserted caliph’s deed and considered him as the murderer. Abu Salt Hiravi was asked: “How did Ma’mun consent to the killing of Imam Reza, even though he respected him and chose him as his successor?”
While confirming the martyrdom of Imam Reza (AS) by the hand of the caliph, Abu Salt stated, “If the caliph respected and praised the Imam was due to the fact that he was aware of the superiority of the Imam, and if he granted him crown prince position in order to pretend that the Imam is materialist and as a result, he would lose the attention of the people, although this did not happen and through the formation of scholarly circles, the image of the Imam and his scientific personality became clear to everyone, and the caliph’s popularity was reduced day by day to the point where the friend and the enemy considered the Imam to be worthy of the caliphate. Hence, he poisoned and martyred the Imam.”
The Imam’s Martyrdom from the Traditions’ Viewpoint
In the context of traditions, which are among the most important historical sources and documents, there are some points about the martyrdom of Imam Reza (AS), including:
In a tradition from Imam Ja‘far Sadiq, it is quoted “A child among my children will be killed in the land of Khorasan”.
In a tradition from Imam Reza (AS), it is stated, “By God, there is not one of us but martyred.” He was told: “Who will kill you?” The Imam said: “The worst people in my time will kill me with poison.”
The most famous and the strongest comment regarding the date of Imam’s martyrdom is on Friday, the last day of the month of Safar 203 AH. The Imam’s blessed age upon martyrdom was 55. The Imam was martyred in the city of Tus and as he himself foresaw and recommended, he was buried at a point in the Sanabad, which later was called Mashhad al-Reza. It was supposed that a child from the generation of the Holy Prophet (pbuh) and an Imam from the Twelvers to be martyred in a land far from the Medina al-Rasul, so that his illuminated shrine would be the one to be visited by millions of devotees, who drink from the guardianship’s clear spring. Peace on him the day he was born, and the day he passed away and the day he shall be raised alive!