大乘起信論義記 3.231

3.231

For instance, according to the habituation of the three evil destinies, they see the Buddha as a three-foot body resembling the leg of a black elephant and the like. Furthermore, as in the case of Trapuṣa and others, they see the Buddha from the position of humans and gods as the body of a tree spirit or a heavenly spirit, and so forth. Based on this, the sentient beings of the six destinies all see the Buddha differently. None of these are supramundane marks, and therefore they are not bliss. Since people of the two vehicles and the like see the Buddha as supramundane, as the body of a noble one such as an arhat, it says, 'that which is seen by ordinary beings' down to 'the response body.'