Through chain of transmission, from Sahl bin Ziyad, from Abdullah bin Al-Husayn, from some companions
Abu Abdullah عليه السلام said: “If a person is cut into two halves, the funeral prayer is performed on the part that contains the heart.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 358