仁王護國般若波羅蜜多經疏 3.210

3.210

解住名者，止觀雙修，緣不能壞，聞說有無，心定不退，名不退住。此亦就勝，唯言有佛無佛心定不退，如彼經說：法及菩薩，聞說有無，定不退也。謂能了知無相即相、相即無相，於佛法中心不退轉。從此第八明童真住。

Exposition: Explaining the name of this abiding: cultivating both calm abiding and insight, conditions cannot destroy it; hearing talk of existence or non-existence, their mind is stable and does not retreat; hence it is called the abiding of non-retrogression. Here too, stated in terms of the supreme, it only says that hearing there is a Buddha or no Buddha, their mind is stable and does not retreat; as that sūtra says: hearing talk of existence or non-existence of the Dharma and bodhisattvas, they are definitely non-regressing. That is, they are able to know that marklessness is marks, and marks are marklessness, and regarding the Buddha-Dharma their minds do not regress. From here is the eighth, explaining the abiding of youthful purity.