阿彌陀經通贊疏 2.124

2.124

贊曰：第二新舊二徒因行有異。文分為二：初新生不退眾、二補處位高眾。此初也。阿鞞跋致，或云阿惟越致，是梵語，此云不退轉。不退有五：一、信不退；二、位不退；三、證不退；四、行不退；五、煩惱不退，不被煩惱所退轉故。

The commentary states: The second [section shows that] the causal practices of both new and old followers differ. The text is divided into two: first, the assembly of the newly born who are non-retrogressing; second, the assembly of high stage who are bound to one birth. This is the first. Avaivartika, or avinivartanīya, is Sanskrit; here it means non-retrogressing. There are five kinds of non-retrogression: first, non-retrogression of faith; second, non-retrogression of stage; third, non-retrogression of realization; fourth, non-retrogression of practice; fifth, non-retrogression from afflictions, because one is not caused to regress by afflictions.