Śatapatha Brāhmaṇa ("of a hundred paths") 3.2.4.1

3.2.4.1

divi vai soma āsīt | atheha devāste devā akāmayantā naḥ somo gacettenāgatena yajemahīti ta ete māye asṛjanta suparṇīṃ ca kadrūṃ ca taddhiṣṇyānām brāhmaṇe vyākhyāyate sauparṇīkādravaṃ yathā tadāsa

Now Soma was in the sky, and the gods were here on earth. The gods desired,--'Would that Soma came to us: we might sacrifice with him, when come.' They created those two illusions, Suparnî and Kadrû. In the chapter on the hearths (dhishnya) it is set forth how that affair of Suparnî and Kadrû came to pass.