觀無量壽佛經疏 3.23

3.23

"Furthermore, with subtle thoughts and coarse thoughts, the water of the mind stirs; once the water of the mind stirs, the tranquil object is lost. Likewise, when fine dust and coarse dust are dropped into quiet water, its ripples stir. Practitioners need only observe whether this water is moving or not moving, and they will recognize whether their own minds are resting or not resting. Furthermore, whether the object manifests or is lost, and whether it is false or correct, are entirely the same as in the sun contemplation above. Also, Vasubandhu's praise says: 'Contemplating the marks of that world, / It surpasses the pathways of the triple realm; / Ultimately like empty space, / Vast and without boundary.' This generally clarifies the measure of the ground of that land."