瑜伽師地論略纂 6.114

6.114

「四因緣故，於人趣中建立如來四眾」者：一、最增上故，謂國王等，即剎帝利；二、世間福田故，謂婆羅門，以多淨行，共許為福田；三、用財不由他，謂大長者；四、棄諸世財，謂諸沙門。此皆佛有，名如來眾。

Regarding 'Due to four conditions, the Tathāgata's four assemblies are established among the human realm': first, because of being the most sovereign, referring to kings and so forth, namely the kṣatriyas; second, because of being worldly fields of merit, referring to the brahmins, who through many pure practices are mutually recognized as fields of merit; third, using wealth without depending on others, referring to the great householders (gṛhapatis); fourth, renouncing all worldly wealth, referring to the various śramaṇas. All of these belong to the Buddha, and are called the Tathāgata's assemblies.