Naturally, it was not possible to fulfil such a promise in view of the difference in the ages of the ruler and his heir apparent, in view of the constant possibility of assassination, and especially in view of what was indicated by al-'Imam al-Rida (A) when he said: “It is a matter that will not be accomplished” and his awareness that al-Ma'mun's moves were not motivated by any conviction that the right to rule should be returned to those worthy of it, but only out of necessity.
Kwa kawaida, haikuwezekana kutimiza ahadi hiyo kwa kuzingatia tofauti ya zama za mtawala na mrithi wake dhahiri, kwa kuzingatia uwezekano wa mara kwa mara wa kuuawa, na hasa kwa kuzingatia yale yaliyoonyeshwa na al-'Imam al. -Rida (A) aliposema: “Ni jambo ambalo halitatimia” na ufahamu wake kwamba hatua za al-Ma’mun hazikusukumwa na imani yoyote kwamba haki ya kutawala inapaswa kurejeshwa kwa wale wanaostahiki. lakini kwa lazima tu.