四分律行事鈔資持記 3.403

3.403

內宿中。二律不犯，皆非意故。本律復開不知不犯，如通塞引。

Under 'Overnight storage within': In the two Vinayas, there is no offense, because both are unintentional. Our own Vinaya further allows an exception for unintentional acts without an offense, as cited in 'Permissions and Prohibitions'.