《太平广记·卷九十二·异僧六》
一行在心里盘算，浑元寺里的工人有几百名，于是叫他们空出一间房子，把一只大缸搬到中间，又暗中挑选了两名常住在这里的仆人，每人送给一个布口袋，叮嘱道： 某某角落有个荒废的园子，你们到里面藏起来等着，从中午到黄昏，会有东西进去，数量是七个，你们要全部抓住。
一行心计浑天寺中工役数百，乃命空其室内，徙一大瓮于中央。密选常住奴二人，授以布囊，谓曰： 某坊某角有废园，汝向中潜伺，从午至昏，当有物入来，其数七者，可尽掩之。
Yixing calculated in his heart that there were hundreds of workers in Hunyuan Temple, so he told them to vacate a room, move a large vat into the middle, and secretly selected two servants who lived here all the time. He gave each of them a cloth bag and asked: There is an abandoned garden in a certain corner. You go in and hide there. From noon till dusk, something will enter, seven in all, which you must catch.