Muhammad ibn Ali ibn Mahbub from Muhammad ibn al-Husayn from Safwan from Iys who said:
I asked Abu Abdillah عليه السلام, peace be upon him, about a man upon whom a year's worth of prayer has accumulated, due to illness. Imam عليه السلام said: “He does not make them up.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 339