瑜伽論記 17.310

17.310

第六明三退。未得退者，未得法不能起得故名退。已得退者，即已得法，退已起煩惱。習行退者，現所得法不起名退。

Sixth, explaining the three regressions. Regression from what has not yet been attained: because one cannot arise and attain what has not been attained, it is called regression. Regression from what has been attained: having regressed from phenomena already attained, one gives rise to afflictions. Regression in practice: what is currently attained does not arise, which is called regression.