MAMOON RASHID'S OFFER OF HEIR TO IMAM REDA (AS)

On Imam Reda's (as) arrival in Marw (Khurasan), the seat of Mamoon
Rashid's caliphate, the Abbasid caliph showed him hospitality and
great respect, then he said to him: "I want to get rid of myself of
the caliphate and vest the office in you." But Imam Reda (as) refused
his offer. Then Mamoon Rashid repeated his offer in a letter saying:
"If you refuse what I have offered you, then you must accept being the
heir after me." But again Imam Reda (as) refused his offer vigorously.
Mamoon Rashid summoned him. He was alone with Al-Fadl ibn Sahl, the
Iranian noble incharge of two offices (i.e., military and civil).
There was no one else in their gathering. Mamoon Rashid said to Imam
Reda (as), "I thought it appropriate to invest authority over the
Muslims in you and to relieve myself of the responsibility by giving
it to you." When again Imam Reda (as) refused to accept his offer,
Mamoon Rashid spoke to him as if threatening him for his refusal. In
his speech he said, "Umar ibn al-Khattab made a committee of
consultation (shura) (to appoint a successor). Among them was your
forefather, the Commander of the faithful, Ali ibn Abi Talib. (Umar
ibn al-Khattab) stipulated that any of them who opposed the decision
should be executed. So there is no escape for you from accepting what
I want from you. I will ignore your rejection of it."
In reply, Imam Reda (as) said: "I will agree to what you want of me as
far as succession is concerned on condition that I do not command, nor
order, nor give legal decisions, nor judge, nor appoint, nor dismiss,
nor change anything from how it is at present." Mamoon Rashid accepted
all of that.
On the day when Mamoon Rashid ordered to make the pledge of allegiance
to Imam Reda (as) one of the close associates of Imam Reda (as), who
was present, narrates, "On that day I was in front of him. Imam Reda
(as) looked at me while I was feeling happy about what had happened.
Imam Reda (as) signalled me to come closer. I went closer to him and
he said so that no one else could hear, 'Do not occupy your heart with
this matter and do not be happy about it. It is something which will
not be achieved.'"