Muhammad bin Ahmad bin Yahya narrated this Hadith as mursal (without a continuous chain of narrators) and added in it:
Imam عليه السلام said: "If it is placed in the grave, then it suffices him."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 348