Is it permissible to retain a piece of food in the mouth during prayer?
Chapter on the Two Prostrations of Forgetfulness
Al-Mughni
Book of Prayer
Primary text
If a worshipper intentionally retains a piece of food (luqmah) in their mouth and does not swallow it, this action is disliked (makruh). The reason for the dislike is that it distracts the worshipper from the necessary state of humility (khushu') required for prayer, remembrance (dhikr), and recitation.
Supporting text
Retaining the food in the mouth does not invalidate the prayer because it is considered a minor action, analogous to holding an object in the hand.