Mantra 13

स नैव व्यभवत् ।स शौद्रं वर्णमसृजत पूषणम् ।इयं वै पूषा ।इयं हीदं सर्वं पुष्यति यदिदं किञ्च ॥बृह. १,४.१३ ॥

In plain words

It still did not flourish. It brought forth the serving class, Pūṣan. This earth is Pūṣan, for it nourishes all this, whatever there is.