7th Imam, Musa Kazim’s (a.s) father is our 6th Imam Jafar Sadiq (a.s) and his mother is Bibi Hamida Khatoon (s.a).
He was given the title Al-Kazim which means ‘someone who swallows his anger.’ One who does not show his her anger is patient.
In 179 AH, Harun ar-Rashid visited Madina. Harun burned with jealousy. He could not bear the Imam’s popularity among the people. He arrested the Imam while he was in the Holy Masjid e Nabi. The Imam was not even given the chance to meet his family and children.
Two litters on camels were brought. The Imam was sent in one and the other empty one was sent to Baghdad. This was to create confusion, so that people did not know where he had been sent. The family of the Imam wept. Imam was handcuffed and shackled and sent to Basra.
At the end of the long journey to Basra, the Imam was handed over to Isa ibn Jafar who was the governor. Isa kept him in the prison for a year but could find no fault with the Imam. The more he observed the Imam, the more convinced he was of the Imam’s nobility.
After a year, Isa wrote to Harun saying he could no longer imprison Imam as he could find only piety and righteousness in him. Harun had moved Imam to Baghdad under the custody of Fadhl bin Rabi who too became a follower of Imam.
The prisons were so small that there was no room to stand and the food was a cup of water and two pieces of dry bread a day.Imam remained patient. Harun also hired mercenaries to kill Imam.They too on seeing Imam wept and refused to murder him even though they were paid to do so.
Harun finally moved Imam into the care of Sindi bin Shahak (a very cruel man). Sindi spared no effort to harass the Imam. He put the Imam in heavy chains, which cut into his ankles and bruised them. He treated the Imam very harshly. But Imam restrained his anger and was patient.
In 183 A.H Harun sent poisoned dates and ordered Sindhi to offer them to Imam Musa Kazim (a.s), who was forced to eat them. The Imam suffered severe pain and knew his meeting with Allah was near. Imam’s soul returned to his Creator on 25th of Rajab 181 A.H. and he was 55 years old.
After Imam’s martyrdom,his Holy body was left on the bridge of Baghdad & an announcement was made for all to come & see him
When Harun’s brother Sulayman heard of this he was furious & arranged for Imam’s burial in a Quraysh cemetery outside Baghdad(8th Imam gave Ghusl and Kafan)
A town grew around the tomb of Imam called Kazimain, meaning the two Kazims – the 7th Imam Musa Kazim (a.s) and the 9th Imam Muhammad Taqi (a.s) in Baghdad, Iraq.

Curse be upon the killers of Imam Musa Kazim (a.s)! Curse be upon Harun Al Rashid!
شہادتامامموسیٰ_کاظمؑ