說無垢稱經疏 5.155

5.155

問：何故方丈變之令廣，世界極小不變令大。答？方丈別室，眾集變之；世界遍處，故不須變。計室論座，大於世界；神力任情，有變不變。

Question: Why did he transform the ten-foot square room to make it expansive, while leaving the extremely small world untransformed and not making it large? Answer: The ten-foot room is a distinct chamber where the multitude gathered, so it was transformed; the world is an all-pervading location, so there was no need to transform it. Measuring the room against the thrones, [the thrones] were larger than the world; spiritual power functions at will, so some things are transformed and some are not.