From him, from al-Husayn, from al-Qasim, from Abu Basir, from Abu Abdillah عليه السلام, peace be upon him, said:
I (narrator) asked Imam عليه السلام about ‘the fasting person chewing gum (ilk)’. Imam عليه السلام said: “Yes, if he wishes.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 4, p. 405