觀無量壽佛經疏 3.19

3.19

答曰：「此界之平水，以對彼地等無高下。又轉水成氷者，對彼瑠璃之地內外映徹也。此明彌陀曠劫等行無偏，正習俱亡，能感地輪之映徹。」

Answer: "The flat water of this realm corresponds to that ground having no heights or depths. Furthermore, transforming water into ice corresponds to that lapis lazuli ground gleaming transparently within and without. This explains that Amitābha's practices throughout vast kalpas were without partiality, with both fundamental defilements and residual habits eradicated, thus able to bring about the transparent clarity of the ground."