Imam Continues His Trip to Marw
The Imam (A.S.) after that continued his trip till he finally reached Marw where al-Mamoon had prepared a comfortable place for him and surrounded him with excellent manifestations of respect and veneration and all means of honouring and glorification. It was then that al-Mamoon started to execute the plan he had planned for the regency.

Imam Preconditions
Finally the Imam (A.S.) bowed his head with the agreement to be the caliph's successor, but it was not before he had taken from the government an excitingly negative stance; he preconditioned that he would not be required to bear any responsibility, general or specific, related to the government and its ruling systems, and al-Mamoon accepted the condition quite reluctantly, but he did try at times to involve the Imam (A.S.) in such responsibilities, and the Imam (A.S.) kept refusing, reminding him to honour his condition.
Having been convinced to accept, the Imam (A.S.) said to al-Mamoon: "I also agree not to name anyone in a post nor remove anyone from a post, that I do not cancel any decree or tradition, and to stay as an advisor," and he agreed to all of that.115
In another encounter, al-Mamoon tried to pressure the Imam (A.S.) into participating in the state affairs; Mu'ammar ibn Khallad said that Abul-Hassan Reza(A.S.) had said to him, "Al-Mamoon said to me, `O father of al-Hassan! You may consider some of those individuals whom you trust to be governors of the areas where corruption is manifest,' and I said to him, `If you honour your part of the agreement, I shall certainly honour mine. I agreed to what I agreed on the condition that I do not issue orders or overrule others, nor depose anyone or appoint anyone, nor do I go anywhere except wherever God sends me. By God! Caliphate was something I never desired, and I used to live in Medina where I go through its alleys on the back of my animal, and when its residents or others ask me to do them a favour, I do them a favour, and thus they become like my own uncles. My letters still carry weight in various lands, and you have not increased me in whatever blessing God has bestowed upon me.' So he said, `I shall honour it.'"116

Analyzing Imam's Negative Stance Towards Such Responsibility
We have no choice here except to clear some of the ambiguity which encompasses this negative stance of the Imam (A.S.) towards the government, for why should he refuse to cooperate with al-Mamoon in carrying out the state affairs?
Before doing anything, we have to evaluate the Imam's viewpoint towards the government and its "legitimacy" under the leadership of al-Mamoon and the counsels of al-Fadl ibn Sahl and his views regarding its leaders and heads.
Of course, his viewpoint was not positive due to his belief that a government was not legitimate as long as it remained distant from his own leadership in his status as the pristine Imam (A.S.) named so by the Messenger (S.A.W.) himself according to a series of instructions conveyed by one Imam (A.S.) to the next. For this reason, we see how his companions unanimously disagreed that he should accept the post of regent which carried an implied recognition of the then caliphate. We can see the only justification they accepted was that the Imam (A.S.) was forced to accept it, and that that post which was forced on him would not change his stance towards the government one iota, for he did not enter into it except like that who entered to exit117 and that what caused him to agree was the same that caused his grandfather the Commander of the Faithful (A.S.) to agree to be part of the shura committee.118
Had Imam Reza(A.S.) wished to share the burdens of government with al-Mamoon, it would have been regarded as his recognition of the legitimacy of the makeup of that government, and an endorsement of all its actions undertaken by its higher authorities, but he preferred to assume the role of an advisor who kept his stances in order to safeguard the interests of Islam the safeguarding of which was his own very mission in life. But the Imam (A.S.) did not want to grant al-Mamoon the status of a custodian over his behaviour and actions, nor would he be the executor of his will and the person to fulfill his every ambition, for he did not have the ambition to achieve a stronger ruling status, or the one who controls the government apparatus, so that he would provide al-Mamoon similarly to what al-Fadl ibn Sahl and others provided. Those individuals used to press to win his favour, flatter him, and carry out his desires whatever they might be so that they would be the first to win a stronger position in the government vehicle.
Let us suppose that the Imam (A.S.) had accepted the principle of taking part in managing the state affairs. That would mean his exposure to an overwhelming and fierce opposition by others who consider Imam Reza(A.S.) as an element differing from their systems in conduct, program, framework and context, and he might push them away from the cycle of government especially since he could not accept all their actions most of which may go beyond the limits legislated for them. Or such a confrontation may expose the Imam's stance to dangerous repercussions which may historically affect his being and personality even if through cheap means and methods they plot behind the scenes to accuse him in order to incite the wrath of the government against him and also distort the sacred halo with which others surround him.
Do these persons lack special means to cast a shadow of doubt on the movements of the Imam (A.S.) and misinterpret his behaviour to the caliph al-Mamoon? Take the case of that person who raised al-Mamoon to the throne after turning the tables upside down on the government in Baghdad, removed al-Amin from his throne through whatever political and military means he had, was he then not capable of plotting to eliminate the Imam (A.S.), or hurt his reputation, in order to secure for himself to remain in the center of power?! In fact, despite the generous amount of intelligence al-Mamoon enjoyed by forcing the Imam (A.S.) to accept regency, the Imam (A.S.) was likewise aware of his situation, keen to the consequences when he practically distanced himself from the areas of responsibility.

Regency Celebrated
When the Imam (A.S.) accepted regency, al-Mamoon wanted to celebrate the event in a grand style, so he conducted a meeting with his closest aides on a Thursday, then al-Fadl ibn Sahl went out and informed the public of the decision al-Mamoon had made regarding Ali ibn Mousa Reza(A.S.) and that he chose him to be his successor and named him "al-Rida" and ordered them to wear green and come on Thursday to swear the oath of allegiance to him as such and take a year's allowance from the state treasury.
On that day, people in their various social classes, leaders, chamberlains, judges and others, all draped in green outfits, rode to the designated place where al-Mamoon had seated himself, putting for Reza(A.S.) two huge pillows. He even spread the carpet in person for Reza(A.S.) and seated him on it near him while wearing a turban and carrying a sword. Then he ordered his son al-Abbas ibn al-Mamoon to be the first to swear allegiance. Reza(A.S.) raised his hand, with its back facing his face and its palm facing them. Al-Mamoon said to him: "Stretch your hand so that people swear allegiance to you." Reza(A.S.) said: "The Messenger of God (S.A.W.) used to put his hand like that before accepting people's allegiance." People swore the oath of allegiance to him while his palm was thus facing them. Tens of thousands of dirhams were brought in; orators delivered speeches and poets said their poems exalting the merits of Reza(A.S.) and the status to which al-Mamoon had chosen him for. Then Abu Abbad called upon al-Abbas son of al-Mamoon. He stood and came close to his father and kissed his hand. His father ordered him to sit, then Ali Muhammad ibn Ja'fer ibn Muhammad was called upon, and al-Fadl ibn Sahl said to him, "Come up," and he did till he was close to al-Mamoon. He stood there but he did not kiss his hand. He was told to go and take his money. Al-Mamoon then called him and told him to go back to his place, which he did. Abu Abbad kept inviting one Alawide and one Abbaside to take their money till all cash was depleted. Then al-Mamoon asked Reza(A.S.) to deliver a sermon.
The Imam (A.S.) praised God and glorified Him, then he said: "We have over you a right designated by the Messenger of God, and you have a right over us as well; so, if you perform your obligation towards us, we will be bound to perform yours."
Historians do not record any other sermon he delivered besides this one on that occasion. Al-Mamoon ordered a new dirham currency to be minted with al-Rida's name on it. Ishaq ibn Mousa ibn Ja'fer married the daughter of his uncle Ishaq ibn Ja'fer ibn Muhammad and ordered him to accompany people to the pilgrimage, and sermons were delivered at al-Rida's home town mentioning his name in them as the designated successor of the caliph.119 Al-Mamoon ordered that all countries must mention Reza(A.S.) during their sermons and pray for him in his capacity as the successor of the caliph of the Muslims.

Poems in his Praise
Poets praised him in a most excellent way. Among such poems were verses composed by Abu Nuwas which are considered the best, for people blamed the poet for not praising Reza(A.S.), whereupon he said: It was said to me that mine was the best rhyme, Articulate in arts of brilliant speech and chime, That I have pearls of beautiful speech Bearing fruits in the hands that can reach; "So why did you leave the praise of the son Of Mousa, and equal to his merits is none?" I said how could I possibly praise and be fair To one whose father Jibreel did serve and care?
Al-Mamoon said: "Very well said," and he paid him as much as he paid all the poets combined and considered him as a close friend. The school of thought of Abu Nuwas was Shi'a, and myths of promiscuity were narrated about and attributed to him regarding which we have our own view which dissociates the poet from what was attributed to him.
Abu Nuwas went out of his house once and noticed that there was a horseman who was riding beside him. He asked who the man was without seeing his face, and he was told that he was Ali ibn Mousa Reza(A.S.), whereupon he instantly composed these verses: Had the eyes sought you for a goal, And the mind doubted you and the soul, The heart would surely you recognize Even when not seen by the eyes.
If people wish to see you but do not know, Your fragrance will tell them where to go.
Once he saw the Imam (A.S.) leaving the court of al-Mamoon and riding his mule, he came close to him, greeted him and said, "O son of the messenger of God! I have composed a few verses about you and would like you to hear them." He said, "Let us hear them," so he said: Cleansed and Purified they are, When mentioned, they are sanctified, Wherever they may be, near or far; When roots and lines are identified, If not Alawides, they indeed are With nothing to boast or pride In their lineage, in their deed; For when God created man and eyed You He selected and favoured indeed And raised above the rest and all With the knowledge of His Qur'an And of its verses you stand tall.
Reza(A.S.) said, "You have composed verses nobody else beat you to them before," then he asked his servant how much spending money he had with him, and the servant told him it was three hundred dinars. The Imam (A.S.) said, "Give it to him all," then he ordered him to hand him his mule as well.120
As regarding Da'bal, the poet of the Ahl al-Bayt (A.S.), I did not come across his poetry in praise of Reza(A.S.) on the occasion, but I have come across his poetry as recorded in books of history which have brought us his famous poem rhyming with the `t' in which he depicted for us the horrible tragedies from which the Ahl al-Bayt (A.S.) suffered the bitterness of injustice and oppression at the hands of their contemporary caliphs and their oppressive rulers. Da'bal seems in his poem to aim at stirring the sympathy of the nation in order to wake up the sense of loyalty to the Ahl al-Bayt (A.S.) and to support them against their enemies who usurped their rights by his magnificent narrative style of the bloody tragedies whereby they were terrorized during various epochs of the Umayyad and Abbaside dynasties. The poem begins with: They answered each other with an echo and sighed, Mourners in non-Arab tongued wailed and cried...
Then he explains the facts the Ahl al-Bayt (A.S.) went through since the demise of the Prophet (S.A.W.), passing by the incident of the saqifa and the nation's stance towards the caliphate then, and ending with the calamity that befell Imam Mousa ibn Ja'fer (A.S.). After that he dedicates the rest of the poem to praising the Ahl al-Bayt (A.S.), highlighting their particular merits and qualities. Imam Reza(A.S.) was moved particularly by two verses of the poem, and that was reflected clearly on his face, when Da'bal said, I find others share their share, Their hands of what is theirs are bare...; the Imam (A.S.) cried and said, "You have said the truth, O Da'bal..." And Da'bal had indeed struck on the Imam's sensitive chord of the dilemma from which the Ahl al-Bayt (A.S.) were suffering when he said: When they were pulled taut, they did stretch Tense hands that couldn't their muscles touch,
the Imam (A.S.) kept making a motion with his hands and repeating, "tense, indeed; they are tense..." The poem is considered one of the best in Arabic poetry in its ease of expression, the reality of exposition, the craftsmanship of its organization, and the excellence of its performance.
When Da'bal finished, Reza(A.S.), according to the author of Al-Aghani, rewarded him with ten thousand dirhams of the ones minted with his name on them, and gave him one of his own shirts which some residents of Qum offered to buy from the poet for thirty thousand dirhams but he refused; therefore, they waited till they had a chance to take it away from him by force. He then said to them, "It is meant to be for seeking nearness to God, the Exalted, and it is prohibited from you," and he swore that he would never sell such a relic except if they agreed to give him a portion of it to put in his coffin, so they gave him one sleeve which was later put inside his coffin.
He wrote his poem titled Madarisu Ayatin, as is said, about a garment (from the Imam) which he wore as the ihram robe, and he ordered it to be put in his coffin upon his death. Da'bal was feared for his tongue, and caliphs used to dread his criticism. Ibn al-Mudabbir said, "I met Da'bal once and said to him, `You have more guts than anyone else when you composed these verses about al-Mamoon:
I belong to the people whose power and might Killed your brother and honoured you with your right; From its long apathy they made your status bright, And lifted you from the deepest pit and plight.
So he said to me, `O Abu Ishaq! I have been carrying my cross board with me during the past forty years without finding anyone to crucify me on it!'"121