翻譯名義集 1.247

1.247

《大論》云：「佛弟子七眾：一、比丘，二、比丘尼，三、學戒尼，四、沙彌，五、沙彌尼，六、優婆塞，七、優婆夷。」然諸經中標四眾者，自古皆以比丘、比丘尼、優婆塞、優婆夷為四眾。天台乃立發起、當機、影響、結緣以為四眾。是則七眾雖別，四眾咸通，七四共成二十八眾。

The Da zhidu lun says: 'The disciples of the Buddha constitute a sevenfold assembly: first, bhikṣus; second, bhikṣuṇīs; third, probationary nuns (śikṣamāṇās); fourth, śrāmaṇeras; fifth, śrāmaṇerīs; sixth, upāsakas; seventh, upāsikās.' However, when the various sūtras designate the 'fourfold assembly,' from antiquity they have always taken the bhikṣus, bhikṣuṇīs, upāsakas, and upāsikās as the fourfold assembly. Tiantai then established the initiating, the intended-capacity, the reflecting, and the condition-forming assemblies to make four assemblies. Thus, although the sevenfold assembly is distinct, the fourfold assembly is comprehensive, and the seven and four together constitute the twenty-eight assemblies.