釋禪波羅蜜次第法門 5.101

5.101

一、退分者，若人得初禪時，或有因緣，或無因緣，而便退失。失有二種：一者、更修還得；二者、更修不得。所謂過去今世障法起故，末世之中，此退分多。

First, the retrogression category: when a person attains the first dhyāna, whether with conditions or without conditions, they retrogress and lose it. There are two kinds of loss: first, cultivating again and regaining it; second, cultivating again and not regaining it. This is because obstructive dharmas of past and present lives arise; in the final age, this retrogression category is common.