分別功德論 5.6

5.6

所以稱難陀迦比丘教授第一者，舍利弗亦教授，普教授四部弟子，從旦至中要使一人至於道迹。此比丘者專教授比丘使得羅漢。譬如善射之人，以一發箭射於彼賊，即中要處便使不起。喻此比丘善誨要慧，聞者結除徑至無為。不善射者，雖用多箭正可一發。喻於身子，雖廣演慧終成一階。優劣之殊格然易見，故言教授後學最為第一也。

As for why the monk Nandaka is declared foremost in instructing: Śāriputra also gave instruction, universally instructing the fourfold assembly of disciples, striving from morning until midday to bring at least one person to the path of realization. This monk, however, exclusively instructed monks so that they attained arhatship. It is like an expert archer who shoots a thief with a single arrow: it strikes the vital spot at once and prevents him from rising again. This is an analogy for this monk's skill in instructing with essential wisdom, so that those who hear it eliminate their fetters and advance directly to the unconditioned. A poor archer, though he uses many arrows, may hit the mark only with one. This is an analogy for Śāriputra, who, though expounding wisdom extensively, ultimately accomplishes only one stage. The difference in their excellence is distinct and easily seen; therefore it is said that he is foremost in instructing junior students.