俱舍論疏 23.103

23.103

「論曰至乃至得解脫」，明極三生也。涅槃名解脫，分是因義，此善順彼與彼作因，故此善名順解脫分。聲聞種姓極速三生，獨覺四生。

From the commentary's statement: "The commentary says ..." up to "... and finally attains liberation": this clarifies the minimum of three lifetimes. Nirvāṇa is called liberation; "part" (*bhāga*) has the meaning of "cause"; these roots of goodness accord with it and serve as its cause, and therefore these roots of goodness are called "conducive to liberation" (*mokṣabhāgīya*). For the śrāvaka disposition, it takes at the fastest three lifetimes; for a pratyekabuddha, four lifetimes.