四分律比丘含注戒本 2.171

2.171

不犯者：不知有蟲，作無蟲想；若蟲大，以手動水令蟲去；若漉水灑地；若教人漉者——一切無犯。

(Regarding non-offense: not knowing there are living creatures and perceiving it as free of creatures; if the creatures are large and one stirs the water with a hand to make them leave; if one strains the water and sprinkles the ground; or if one tells another to strain it—in all cases there is no offense.)