Jaiminīya Upaniṣad Brāhmaṇa 1.2.2

1.2.2

sa ya evaṃ vidvān udgāyaty om ity evāgnim ādāya pṛthivyām pratiṣṭhāpayaty om ity eva vāyum ādāyāntarikṣe pratiṣṭhāpayaty om ity evādityam ādāya divi pratiṣṭhāpayaty om ity eva prāṇam ādāya vāci pratiṣṭhāpayati /

He who sings the udgītha knowing thus, taking Agni with 'om', establishes him in the earth; taking Vāyu with 'om', establishes him in the intermediate space; taking Āditya with 'om', establishes him in heaven; taking breath with 'om', establishes him in speech.