典故as poor as a church mouse 的来历是什么?

as poor as a church mouse 教堂 ( church ) 是教徒们进行宗教活动的地方,教徒们虔诚地作礼拜,当然没有人在这里吃东西,自然也不会有食品橱,一切都为得庄严肃穆。所以老鼠想在教堂里找吃的东西,根本的枉费心机,教堂里的老鼠 ( a church mouse ) 是非常穷的,所以就有 as poor as a church mouse 的说法,指某人一贫如洗。