俱舍論記 7.122

7.122

「若依未至至唯自非餘地」者，此明無學九地出心，若身在欲界依未至定，得阿羅漢果後出觀心。若於彼定得自在者，或即彼地；若於彼定不得自在，或起欲界。若身生初地得阿羅漢果，後出觀心唯起自地。若身生有頂，依無所有處得阿羅漢果，後出觀心定是有頂，必不能起下有漏心。所以者何？異熟生心無異地起，下地煩惱已斷不行。又不起下善有漏心故，定起彼有頂地善心。若身生下地，依無所有處得阿羅漢果，或即彼地出非餘地，以於彼地得自在故。若依中間餘地得羅漢果，後出觀心，唯起自地非餘地心，皆於彼地得自在故。所以即彼地心出，無異地心出。問：若依第二定等得阿羅漢果，後出觀心，何故不或即彼地、或起下地？解云：若欲界散心是強，眾生無始多生其中數數串習，起時即易。有依未至定不得自在者，容起欲界散心。上二界定及與散心，有情無始不多生彼，初無學後異地相生起時即難，當地即易。故依二定等得無學果，後出觀心，唯依自地，不依下地定及散心。

As for "If relying on the threshold … only one's own, not another level": this explains the mind emerging across the nine levels of the aśaikṣa. If the body is in the desire realm and, relying on the threshold concentration, attains the fruit of arhatship, in the subsequent mind emerging from contemplation: if one has attained mastery over that concentration, it is perhaps of that very level; if one has not attained mastery over that concentration, one perhaps arises [a mind of] the desire realm. If the body is born in the first level and attains the fruit of arhatship, the subsequent mind emerging from contemplation arises solely from its own level. If the body is born in the peak of existence and, relying on the sphere of nothingness, attains the fruit of arhatship, the subsequent mind emerging from contemplation is definitely of the peak of existence, and certainly cannot arise a lower sāsrava mind. Why is this? The mind born of karmic maturation does not arise in a different level, and lower-level defilements have already been severed and do not become active. Furthermore, because one does not arise a lower good sāsrava mind, one definitely arises a good mind of that level of the peak of existence. If the body is born in a lower level and, relying on the sphere of nothingness, attains the fruit of arhatship, it emerges perhaps in that very level and not another level, because one has attained mastery over that level. If relying on the intermediate or remaining levels one attains the fruit of arhatship, the subsequent mind emerging from contemplation arises solely from its own level and not from the mind of another level, because in all cases one has attained mastery over that level. Therefore one emerges in the mind of that very level, and does not emerge in the mind of a different level. Question: If relying on the second dhyāna and so forth one attains the fruit of arhatship, in the subsequent mind emerging from contemplation, why does one not perhaps [emerge in] that very level or arise a lower level? The explanation is: The scattered mind of the desire realm is strong; sentient beings from beginningless time have mostly been born therein and repeatedly habituated to it, so when it arises it is easy. For those who rely on the threshold concentration and have not attained mastery, it is permissible to arise the scattered mind of the desire realm. As for the concentrations and scattered minds of the upper two realms, sentient beings from beginningless time have not mostly been born there; when initially an aśaikṣa, mutual arising across different levels afterwards is difficult, while in the same level it is easy. Therefore, relying on the second dhyāna and so forth to attain the fruit of an aśaikṣa, the subsequent mind emerging from contemplation relies solely on its own level, and does not rely on the concentrations and scattered minds of lower levels.