《笑林广记·谬误部》
主人在自家墙上画一乌龟，目的是禁止他人屙屎撒尿，有个人竟然照样在此撒尿。
墙上画一乌龟，专禁人屙溺，一人竟撒。
A master drew a turtle on the wall of his house, with the aim of stopping other people from doing their business there, but there was one man who nevertheless urinated there.