Imam Reza (as) Martydom -1

Al-Ma’mūn sent for the Imām Reza (as). When the Imām came, al-Ma’mūn rose for him, embraced him, kissed him on the forehead, seated him beside him, conversed with him, ordered one of his retainers to bring him grapes and pomegranates.
Herthama said: “I became impatient and shook (with fear).”
Al-Ma’mūn gave a bunch of grapes to the Imām and said to him: “O son of Allah’s Messenger, I have never seen grapes better than these.”
“Perhaps, there are grapes better than them in the Garden,” retorted the Imām.
Al-Ma’mūn asked the Imām to have some grapes , and he refrained from having them, so al-Ma’mūn shouted at him: “Perhaps, you are accusing as of something.”
The Imām ate three grapes, then he threw them away and rose, so al-Ma’mūn asked him: “Where are you going?”
“To my house,” replied the Imām.
The Imām went in a hurry to his house. The poison acted on all parts of his body, and he was sure of the coming down of the fatal misfortune. Al-Ma’mūn sent for him and asked him for sincere advice, and he, peace be on him, said to his messenger: “Say to him (al-Ma’mūn): He (al-Ridā) advises you not to give anyone anything for which you must repent.”
The poison circulated through all parts of the Imām’s body, and he suffered from severe aches. He came to know that he was about to meet his Lord. So he recited some verses of the Holy Qur’ān, asked Allah’s forgiveness, and supplicated for the believers, male and female. The narrators have said: “When he was in a critical condition, his household and his companions refrained from having food and drink.”
So he, peace be on him, turned to Yāsir and asked him: “Have the people eaten anything?”      
  He answered him with a faint voice with sad tones, saying: “Who can eat while you are in a critical condition?”
He, peace be on him, rose, and then he said: “Bring me the food; he seated all his servants around the food; and reviewed them one by one. When they had finished eating, he ordered them to carry him to his womenfolk. When they had finished eating, he fainted

Reference :The life of Imām'Ali Bin Mūsā al-Ridā