法華玄論 7.93

7.93

問：佛有二種光。一常光，初生至滅常自有之，即丈光相。二非常光，隨時示現。一音說法令萬類異解，為是常音、為是示現？

Question: The Buddha has two kinds of light: first, the constant light, which he constantly possesses naturally from his initial birth until extinction, which is the ten-foot light mark; second, the non-constant light, which is manifested according to the occasion. Is expounding the Dharma with a single sound to cause myriad kinds [of beings] to have different understandings this constant sound, or is it a manifestation?