After the death of Imam Ali ibn Musa al-Reza (A.S.), Mamun, the Abbasid caliph was under constant criticism by his subjects who blamed him for Imam (A.S.)'s death. In order to keep the situation calm and regain the confidence of his people, Mamun invited Imam Muhammad ibn Ali al-Taqi (A.S.)to Baghdad. He also sent some people to escort the Imam (A.S.)to show the people that he accorded high respect to the Ahlul-Bayt (A.S.). At that time, the age of the Imam (A.S.)was barely 7 to 9 years.
When the Imam (A.S.)arrived in Baghdad and prior to his meeting with Mamun, he was once among the children of his age playing on the road when suddenly they all saw Mamun approaching. They quickly dispersed from the place and hid themselves except for Imam al-Taqi (A.S.). Mamun asked him, "Why haven't you run away like everybody else?" Imam (A.S.)replied, "The path is not narrow that it would become wider by me moving away from it, nor have I committed any crime that I should run away from you. And I don't think that you are the sort who would punish an innocent person!"
Seeing the handsome and illuminated face of the young boy and listening to his bold reply, Mamun was wonderstruck. Therefore, he asked, "What is your name?" The young boy replied, "Muhammad" "Whose son are you?" asked Mamun. "I am the son of Ali ibn Musa al-Reza (A.S.)" replied the young boy. When Mamun heard this, he praised the eighth Imam (A.S.)and went away.
After this brief encounter, Mamun proceeded to the forest. There, he released his eagle which flew and came back with a live fish in its beak. Mamun was surprised by this. As he was returning to his palace, Mamun passed by the same spot where he had met Imam al-Taqi (A.S.)earlier on. He noticed that the boy was still there. Addressing him, Mamun asked, "O Muhammad! Tell me what do I have in my hand?"
The Imam (A.S.)replied, "Allah (SWT) has created many vast oceans from which clouds are formed. When clouds are forming, they absorb small live fishes which are sought by the eagles of the kings who then use them to test the Imams of their time". Hearing this, Mamun admitted, "There is no doubt that you are the son of Ali ibn Musa (A.S.), for such miracles are only possible by his son". (Ahsan al-Maqaal)
The Imams from the progeny of the Holy Prophet (saww) did not possess apparent kingdoms and never ruled or behaved like other kings but they were always in enviable position because of their God given status. Even the kings and the rulers were jealous of them.
"Or do they envy the people for what Allah has given them of His grace? But indeed We gave Ibrahim's children the book and the wisdom and We gave them a great kingdom". (4:54)
It was the house of Prophet Ibrahim (A.S.)which was promised leadership in religion and greatness as a nation. "The children of Ibrahim" in this verse refers to the offspring of his son Ismail (A.S.)who are the Holy Prophet (saww) and his holy progeny who were given the book, the wisdom and a great kingdom.
Imam Ja'ffar al-Sadiq (A.S.)was asked about the above verse as to who this people are on whom others are jealous and he (A.S.)replied, "We are those upon whom our enemies are jealous of". (Tafseer-e-Namoona)

JEALOUSY:
Hasad which means "jealousy" is a very dangerous spiritual disease. A Jealous is he who will always wish and also work with evil schemes to eliminate the bounties from others regardless of whether he for himself, gets those bounties or not. In the words of Ameer al-Mumineen (A.S.), "A jealous is he who considers the disappearance of bounties from those he is jealous about, as a bounty for himself". (Ghurar al-Hikam)
Such a person invites several problems for himself. Some of them are:-
He is never happy in this life. He is always burning within himself and he is continuously in grief.
Imam Ali (A.S.)has said, "I have never seen an oppressor who resembles an oppressed other than one who is jealous". (Tuhaf al-'Uqool)
In another tradition, the Imam (A.S.)has said, "It is sufficient for you to know that one who is jealous about you is grieving during your happiness". (Bihar)
Jealousy has an adverse effect on one's physical health.
It has been proved today certain psychological elements have negative implications upon a person's physical health too. For instance, a person who is under dire stress may become prone to diseases such as diabetes or even heart problems.
Imam Ali (A.S.)says, "The health of the body is from less of jealousy (in man)". (Tafseer-e-Namoona) In another tradition, he (A.S.)says, "I am surprised about the negligence of jealous people regarding the well being of their bodies". (Tafseer-e-Namoona)
Jealousy can become the cause of destruction in the hereafter.
Jealousy is so dangerous that if it is not controlled, it can lead one to disbelief in Allah (SWT) and self-destruction in the hereafter.
Abu Laylah was a chief justice in the court of Mu'tasim, the Abbasid caliph. One day, he came to his friend Zarqa in state of extreme anger and when asked the purpose of anger, Abu Laylah said, O Zarqa! Today I was put to a very big test in which I failed. A thief, whose crime was established, was presented before Mu'tasim. Therefore, Mu'tasim asked, 'Quran says that I should cut the hands of this thief. You tell me from which part shall his hand be cut-off'. I said, ' Quran states tha chop-off the hand of a thief and in the verse of wudhoo, it is mentioned that wash your hands till your elbow. So from elbow downwards is considered as hand therefore cut his hand from his elbow'.
Mu'tasim then asked other learned people in his court for their opinion. Someone said, 'In the verse of Tayammum, hand has been mentioned till the wrist so cut the thief's hand from his wrist'. After a lot of discussion and debate, Mu'tasim then put the same question to the Imam of the shia'hs, Muhammad ibn Ali, who happened to be present at the time. At first, he refused to comment but when Mu'tasim insisted, he said, "You will only cut-off the fingers of the thief because Quran says: The places of prostration are for Allah meaning parts of the body placed on the ground during Sajda. Since the thief is also a Muslim who offers prayers, he will need his palms during Sajda. So you have to leave that and cut only his fingers".
O Zarqa! Mu'tasim was so pleased with the answer that he praised the Imam of the Shia'hs and we felt discredited. O Zarqa! I am aware that whoever harms this young man will burn in the hell-fire but I will not rest till I have taken my revenge against him} Having said this, Zarqa returned to Mu'tasim to provoke him against the Imam (A.S.). He said to him, "What have you done? People as it is believe in him as the true Imam and do not believe in you. Why did you give preference over us? Now you have confirmed to the people through your action that indeed he is on truth and you are on falsehood". Mu'tasim was so effected by this, that shortly after this incident, he poisoned the Imam (A.S.). (Bikhre Moti)
Imam Muhammad al-Taqi (A.S.) passed away in Dhul-Qa'dah 220 AH.