大乘起信論裂網疏 4.80

4.80

但隨眾生見聞等故，而有種種作用不同。此用有二：一、依分別事識。謂凡夫二乘心所見者，是名化身。此人不知轉識影現，見從外來，取色分限。然佛化身無有限量。

"However, merely according to sentient beings' seeing, hearing, and so forth, there are various different functions. This function is twofold: first, relying on the discriminating object-consciousness. That which is seen by the minds of ordinary beings and [followers of] the two vehicles is called the transformation body. These people do not know that it is a shadow-image appearing from the transforming consciousness; seeing it as coming from the outside, they grasp at limits of form. However, the Buddha's transformation body has no limitation."