四分律比丘含注戒本 3.269

3.269

不犯者：有病；或食中有草、有，或有不淨污，或有未受食，捨棄之。

There is no offense for: one who is ill; or if there is grass or [insects] in the food, or if there is an impure smudge, or if there is unreceived food, and one casts it aside.