四分律比丘含注戒本 2.485

2.485

不犯者，得二宿，至第三宿明相未出，離聞見處。若水陸道斷，命、梵等難，不離，無犯。

(Those who do not commit an offense: having stayed two nights, before the first light of dawn comes out on the third night, he leaves the place of hearing and sight. If water or land routes are cut off, or if there is danger to life, brahmacarya, etc., and he does not leave, there is no offense.)