俱舍論記 25.66

25.66

「論曰至可委信處」者，釋上兩句。此明退果必不命終，如文可知。問：退果不命終，何故退向即有命終？答：如《婆沙》六十一云「復次根本果位具五因緣：一捨曾得道、二得未曾得道、三證結斷一味得、四頓得八智、五一時修十六行相，故退果時若未還得，無命終理。向中不爾，故退彼時雖未還得，有命終義。」廣如彼釋。

"The treatise states... a trustworthy place" explains the upper two lines. This explains that one who falls away from the fruit definitely does not die [before regaining it], as is clear from the text. Question: If one who falls away from the fruit does not die, why is it that when one falls away from the path of practice (pratipannaka) there can be death? Answer: As the Vibhāṣā says in fascicle 61: "Furthermore, the fundamental state of the fruit possesses five causal conditions: first, abandoning previously attained paths; second, attaining paths not previously attained; third, realizing the single-taste acquisition of the severance of defilements; fourth,頓 attaining the eight knowledges all at once; fifth, simultaneously cultivating the sixteen aspects. Therefore, at the time of falling away from the fruit, if it has not yet been regained, there is no principle of dying. In the path of practice this is not the case; hence when one falls away from that, although one has not yet regained it, there is the possibility of dying." It is explained at length as therein.