觀無量壽佛經疏 3.17

3.17

答曰：「日輪常照，以表極樂之長暉。復恐彼地不平，類此穢國之高下。但以娑婆闇宅，唯日能明。此界丘阬未無高下之處，欲取能平之者，無過於水。示斯可平之相，況彼瑠璃之地也。」

Answer: "The sun disk shines constantly, signifying the enduring radiance of Sukhāvatī. Furthermore, fearing that that ground might be uneven, like the heights and depths of this defiled land—yet, as the Sahā world is a dark abode, only the sun can bring light; and in this realm of hills and pits, there are nowhere without heights and depths—if one wishes to take something that can be level, nothing surpasses water. Displaying this mark of what can become level illustrates that lapis lazuli ground."