As famously reported, Al-Rashid brought fresh dates and put a deadly poison into them. He ordered Al-Sindi to offer them to the Imam (a.s) and to force him to eat some of them. It is also quoted that Al-Rashid ordered Al-Sindi to buy and poison the dates himself. So, he took fresh dates, put poison into them, and offered them to the Imam (a.s). The Imam (a.s) ate ten fresh dates, and Al-Sindi said to him, “Eat more (dates) than that! The Imam (a.s) looked at him and replied, “I ate enough. You have achieved what you desired.”. The poison started to work upon entering the Imam’s (a.s) body. He (a.s) started to suffer from severe pain and aches, as the poison started to burn his sacred intestines. He kept suffering the unbearable pain for two days until his holey soul left his pure body. He passed away alone; no family, no companions, no dear ones beside him. (1)
Al-Shiekh Al- Mufid states, “The people began to come and look into (Imam Musa's) face while he was dead. Since, during the life of Imam Musa Al-Kadhim (a.s) a group had claimed that he was the awaited Imam (al- Muntazar) who would continue to undertake the Imamate for the rest of time. They made his imprisonment the period of occultation (al-ghayba) which had been reported concerning the last Imam (al-qa’im). Yahya ibn Khalid ordered it to be announced at his death: “This is Musa ibn Ja’far whom the Rafidites claim to be the last Imam (al-qa’im) who will not die. So (come and) look at him.”
The people saw that he was dead. Then he was carried away and buried in the cemetery of Quraysh at the Tin Gate. This cemetery had been used for Banu Hashim and the nobles of the people for a long time.” (2)
(1) View The life of Imam Musa al-Kazim vol. 2.
(2) Al-Irshād, vol. 2, p. 215.