首楞嚴義疏注經 9.23

9.23

從前少光，更發多光，光相轉增名光光相然。光相圓明映十方界，境隨光淨遍成琉璃，由定漸增，定光發照必無涯際，名無量光。

From the previous lesser light, yet more light is emitted; the manifestations of light multiply, which is called "light and light ignite each other." The manifestations of light are perfectly luminous, illuminating the worlds of the ten directions; the environment purifies with the light, everywhere becoming lapis lazuli. Due to meditative absorption gradually increasing, the light of meditative absorption shining forth must be without boundary, hence named Limitless Light.