Jaiminīya Upaniṣad Brāhmaṇa 1.37.2

1.37.2

sā yā mandrā sāgneyī
tayā prātassavanasyodgeyam
āgneyaṃ vai prātassavanam āgneyo 'yaṃ lokaḥ
svayāgayā prātassavanasyodgāyaty ṛdhnotīmaṃ lokam /

That which is low is pertaining to Agni; with it one should chant the morning pressing. The morning pressing belongs to Agni, and this world belongs to Agni. With its own tone one chants the udgītha of the morning pressing, and prospers in this world.