Narrated from Fadalah, from Abdullah ibn Sinan, from Abu Abdullah عليه السلام, who said:
Imam عليه السلام said: "The cloak is not to be wrapped around (the deceased), but rather it should be placed over him as a covering. And when he is placed in the grave, it should be positioned under his cheek and under his side."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 461