Śatapatha Brāhmaṇa ("of a hundred paths") 8.7.2.6

8.7.2.6

lokam pṛṇa cidram pṛṇeti | lokaṃ ca pūraya cidraṃ ca pūrayetyetadatho sīda dhruvā tvamityatho sīda sthirā tvam pratiṣṭhitetyetadindrāgnī tvā bṛhaspatirasminyonāvasīṣadannitīndrāgnī ca tvā bṛhaspatiścāsminyonau pratyatiṣṭhipannityetadanuṣṭubhā vāgvā anuṣṭubvāgindra indro lokampṛṇā na sādayatyasanno hyeṣa sūdadohasā vadati prāṇo vai sūdadohāḥ prāṇenaivainametatsaṃtanoti saṃdadhāti

[He lays them down, with, Vâg. S. XV, 59], 'Fill the space! fill the gap!'--that is, 'fill up the space! fill up the gap;'--'and lie thou steady!'--that is, 'and lie thou firm, settled!'--'Indra and Agni, and Brihaspati, have settled thee in this womb;' that is, 'Indra and Agni, and Brihaspati, have established thee in this womb.' Thus (he establishes them) by an anushtubh verse; for the Anushtubh is speech, and Indra is speech, and the space-filler is Indra. He does not settle them, for that (sun) is unsettled. He pronounces the Sûdadohas on them, for the Sûdadohas is vital air: he thus makes him (Agni) continuous and joins him together by means of the vital air.