From him, from Ahmad, from al-Barqi, from Jafar ibn al-Muthanna, from Ishaq ibn Ammar, who said:
I (narrator) said to Abu Abdillah عليه السلام, peace be upon him: “May I eat during the night in the month of Ramadan until I doubt?” Imam عليه السلام said: “Eat until you do not doubt.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 4, p. 397