俱舍論疏 25.28

25.28

論「若住此位至必亦無退」，明無學、有學二。先位中是其退法，至修道位中，從退至思等，從思至護等，此新進得種性有容退義。無學有學二，先位中住思護、住堪達種性，至無學位必無退義，經二道持皆不退故。

On the Śāstra's statement: "If one abides in this position ... one also definitely does not fall away": This explains the two, the adept and the trainee. If one was in the position of being liable to fall away in earlier stages, and in the stage of the path of cultivation advanced from falling away to reflection and so on, or from reflection to preservation and so on, these newly attained lineages admit the possibility of falling away. If in both the adept and trainee stages one previously abided in reflection or preservation, or abided in the lineage of being able to penetrate, upon reaching the stage of an adept one definitely does not fall away, because having been maintained through both paths, one does not fall away in either case.