四分律行事鈔資持記 2.1194

2.1194

不犯中。上二非食。若不下，治病。若乞下，開物墮。麁者可除；或不可辨，理應再受。餘即除不盡者，準上《善見》細塵更受，以一向不可除故。

Under non-offense: the former two are not food. From "if not" onwards, it is curing illness. From "if begging" onwards, it permits when an object falls into it. What is coarse can be removed; or if it cannot be discerned, by principle it should be received again. "Remainder" refers to what cannot be fully removed; based on the Samantapāsādikā above, for fine dust it must be received again, because it can by no means be removed.