俱舍論疏 10.236

10.236

論「無記勢力微順心斷故」，答所以也。《正理論》云「劣善何故不入涅槃？以彼善心有異熟故。諸阿羅漢厭背未來諸異熟果，入涅槃故。若爾，住異熟應不入涅槃。不爾，已簡言厭背未來故。何不厭背現在異熟？知依現異熟，永斷諸有故。依現異熟證無學果，知彼有恩不深厭患。諸阿羅漢深厭當生，故命終時避彼因善，唯二無記，勢力劣故。順於昧劣相續斷心，故入涅槃唯二無記。」

On the passage in the treatise "Because the power of the morally indeterminate is weak and accords with the cessation of the mind": this answers the reason. The Nyāyānusāra states: "Why does an inferior wholesome [mind] not enter nirvāṇa? Because that wholesome mind has vipāka. Arhats, being averse to all future fruit of vipāka, enter nirvāṇa. If so, then one dwelling in vipāka should not enter nirvāṇa. That is not so, for it was already qualified by saying they are averse to the future. Why are they not averse to present vipāka? Because they know that relying on present vipāka, they permanently sever all existences. Relying on present vipāka, they realize the fruit of no-more-learning (aśaikṣaphala); knowing it has been of benefit, they do not feel deep aversion. Arhats feel deep aversion toward future rebirth, and therefore at the time of death they avoid that wholesome cause; only the two indeterminate [minds], because their power is weak, accord with the dull and inferior mind whose continuum ceases. Therefore, entry into nirvāṇa is only with the two indeterminate [minds]."