妙法蓮華經玄義 7.83

7.83

有三義故，得知諸土悉迹土也：一、今佛所栖故。二、前後修立故。三、中間所拂故。若是本土，非今佛所栖，今佛所栖，即迹土也。若是本土，一土一切土，不應前、後修立，深、淺不同；今土已前，本土已後，皆名中間，中間悉稱方便，況今之土，寧得非迹？從本垂迹，執迹為本者，此不知迹亦不識本。今拂迹指本，本時所栖四土者，是本國土妙也。迹本非本，本迹非迹，非迹非本，即不思議一也。

Because of three points, we know that all these lands are trace lands: First, because they are inhabited by the present Buddha. Second, because they are established sequentially earlier and later. Third, because they are brushed aside as intermediate. If it were the original land, it would not be inhabited by the present Buddha; being inhabited by the present Buddha, it is a trace land. If it were the original land, one land would be all lands, and they should not be established earlier or later with differences of depth and shallowness. The time before the present land and after the original land is all called the intermediate; all within the intermediate is termed expedient means. How then could the present land not be a trace? Dropping traces from the original source, if one grasps the traces as the original source, one neither understands the traces nor recognizes the original source. Now, brushing aside the traces to point to the original source, the four lands inhabited at the original time are the wonderfulness of the original land. The traces of the original are not the original, the original of the traces is not the traces, and being neither trace nor original is the inconceivable unity.