There is none of us, except that he will be killed and martyred

بسم الله الواحد القهار

Sheikh As-Saduq:

Mohammad Ibn Musa Ibn Al-Mutawakkil - may God be pleased with him - narrated that Ali Ibn Ibraheem Ibn Hashim quoted on the authority of his father, on the authority of Abi Salt Al-Hirawi who said: I heard Al-Ridha(عليه السلام) saying, “By Allah! there is none of us, except that he will be killed and martyred.”
He was asked, “O son of the Prophet of God! Who will murder you?” He replied, “The most wicked creature of God in my time (Al-Ma’mun) will kill me using poison. Then he will bury me in a very tight house in a strange town. Know that whoever visits me in my loneliness, God the Highest will record for him the reward of one-hundred thousand martyrs, one-hundred thousand honest ones, one-hundred thousand obligatory and ‘Umra (supererogatory) pilgrimages, and one-hundred thousands fighters in the way of God. He will also be resurrected among us. He will be established in high ranks in Heaven as our friend.”

Source: Amali As-Saduq, S. 15, Pg. 57, H-No: 8

Grading: Sahih(Authentic)

Check Rijaal section:

1794: Mohammad Ibn Musa Ibn Al-Mutawakkil
1193: Ali Ibn Ibraheem Ibn Hashim Al-Qummi
53: Ibraheem Ibn Hashim Al-Qummi
1012: Abdus-Salaam Ibn Saleh, Abu Salt Al-Hirawi