釋禪波羅蜜次第法門 5.171

5.171

答曰：前後皆有所以。今約發說，彼據成就而立，例如三禪立樂支，前後不定。

Answer: Both earlier and later arrangements have their reasons. Here it is explained in terms of its initial arising, whereas there it is established based on its completion; just as, for example, the establishment of the factor of pleasure in the third dhyāna is variable in its order.