大乘起信論裂網疏 3.8

3.8

Question: If you say that east and west have fixed directions, why does the Mahāprajñāpāramitopadeśa refute this, saying: 'If where the sun rises is east, then for Uttarakuru the sun sets there, and it is again called west. For Pūrvavideha the sun is at noon there, and it is again called south. For Aparagodānīya the sun makes midnight there, and it is again called north.' Now you speak of fixed directions; how can this be coherent? Answer: In general, metaphors are based on what is commonly known before people's eyes, using the easy to illustrate the difficult and the shallow to describe the deep, nothing more. Just as the full moon is a metaphor for a face, how could one seek eyebrows and a nose on it? A snowy mountain is a metaphor for an elephant, how could one demand a tail and tusks from it? However, what you have cited all the more reveals the profound meaning. If based on this continent, then east and west are fixed, and outside of the fixed directions there is no other mark of knowing, which can serve as a metaphor for there being no wisdom outside of suchness. If considered in terms of the four continents, then east and west are unfixed, names being established according to what sentient beings each know, and outside of what is known there is no separate real direction, which can serve as a metaphor for there being no suchness outside of wisdom. If they mutually negate, both perish; hence it is said that nothing at all is apprehended, being free from the marks of the two graspers. If they are simultaneously illuminated, they are distinctly apparent; hence it is said there is only tathatā and the wisdom of tathatā.