Imam Muhammad al-Baqir(A.S), had carried out his immortal message: he had spread knowledge and Islamic manners among people. Then Allah chose him to be His neighbor. He wanted him to enjoy the shade of His mercy and His gardens. He wanted him to be happy through meeting his grandfathers, who passed the methods of justice and fairness in the earth.

The Imam announced his own Death
The Imam felt the approach of his certain death. So, he hurried to his aunt, Fatima daughter of Imam al-Husayn, peace be on him. He announced his death to her, saying: "I have completed fifty-eight years.(1. Tadhkirat al-Khawas, p. 350. In Kashf al-Ghumma, vol. 2, p. 322, it has been reported on the authority of Imam Ja'far al-Sadiq, peace be on him, who said: [ My father Mohammed al-Baqir, peace be upon him, said] " Ali was killed at the age of fifty-eight, 'Ali b. al-Husayn died at the age fifty-eight. I am fifty-eight years old.).
Fatima understood what the Imam meant. Her heart melted with sorrows for her nephew. For he was the rest of the members of his family, who were killed by the swords of aggression and error. The Imam completed fifty-eighty years full of misfortunes. Those years filled his heart with sorrow and sadness. His father, Imam Zayn al-'Abidin, and his grand father, Imam al-Hasan, peace be on them, departed life at the same age. Thus, the Imam felt that he was about to die.

The Martyrdom of the Holy Imam(A.S).
Imam Muhammad al-Baqir(A.S), did not die a natural death. Rather, some sinful persons, who did not believe in Allah and the hereafter, gave him poison to drink. The historians differed over which sinful person who committed such a crime. The following are some of the view:
Hisha`m b. al-Hakam gave the Imam poison to drink.(Bihar al-Anwar)1
This is the most acceptable view. For Hisha`m was the most spiteful person towards the family of the Prophet. His soul was full of malice and hatred towards Ahlul bayt. It was he who forced the great martyr, Zayd b. 'Ali, peace be on him, to revolt against him. That was when he scorned and abandoned Zayd.
Surely, the great Imam Muhammad al-Baqir(A.S), shook the position of this tyrannical person (Hisha`m). That because the Imam's knowledge and outstanding merits were famous. So, the Moslems talked about his talents and abilities.
Hence, Hisha`m killed the Imam to get rid of him. (Akhbar al-Duwal, p. 111).
Ibra`him b. al-Walid gave the Imam poison to drink. Sayyid b. Tawu`s thought that Ibra`him b. al-Walid took part in murdering the Imam, (Bihar al-Anwar)
This means that Ibra`him helped other persons to murder the Imam, peace be on him
Some references have ignored the name of the person who assassinated the Imam, peace be on him. They have only mentioned that the Imam died of poisoning.( Nur al- Abbsar, vol. 131. Ibn Tolan, al-A'imma al-Ithna 'Ashar, p. 281)
These are some of the views mentioned concerning murdering the Imam, peace be on him, with poison.