俱舍論疏 25.86

25.86

論「無退論者至不應為難」，無退論者，謂經部等。諸無漏解脫皆名不退，如何經中說六種姓？如前通云：據有漏現法樂說。

Regarding the treatise text “Those who maintain non-falling-away […] should not raise this objection”: “those who maintain non-falling-away” refers to the Sautrāntikas and others. [For them,] all undefiled liberations are called non-falling-away; why then does the sūtra speak of six lineages? As resolved earlier: it is spoken in terms of defiled pleasant abiding in the present life.