仁王經疏 3.152

3.152

釋曰：第二辨類差別。略辨四眾：一婆差、二優婆差、三比丘、四比丘尼。言婆差者，或云優婆塞，皆訛略也。正言鄔波索迦，此云近事男。鄔波斯迦，此云近事女。索是男聲，斯是女聲。謂彼恒時親承善士，故名近事，廣釋如前。比丘及比丘尼，亦如前釋。

Explanation: Second is distinguishing their categories. It briefly distinguishes the four assemblies: first, pocha; second, youpocha; third, bhikṣus; fourth, bhikṣuṇīs. As for the word pocha, or upāsaka, these are all corrupt abbreviations. Correctly speaking, it is upāsaka, which here means "a lay man who approaches and serves"; upāsikā here means "a lay woman who approaches and serves." The -ka is a masculine ending and -kā is a feminine ending. Because they constantly draw near and attend upon good persons, they are called "those who approach and serve"; the detailed explanation is as before. Bhikṣus and bhikṣuṇīs are also explained as before.