Ali ibn Ibrahim narrated from his father, from al-Nawfali, from al-Sakuni, from Imam Ja’far Al Sadiq عليه السلام, from his father Imam Al Baqir عليه السلام:
Imam عليه السلام said: "Whoever enters the grave should not exit from it except from the side of the feet."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 335