Śatapatha Brāhmaṇa ("of a hundred paths") 9.2.3.14

9.2.3.14

athāśmānam pṛśnimupadadhāti | asau vā ādityo 'śmā pṛśniramumevaitadādityamupadadhāti pṛśnirbhavati raśmibhirhi maṇḍalam pṛśni tamantareṇāhavanīyaṃ ca gārhapatyaṃ copadadhātyayaṃ vai loko gārhapatyo dyaurāhavanīya etaṃ tadimau lokāvantareṇa dadhāti tasmādeṣa imau lokāvantareṇa tapati

He then sets up a variegated stone;--the variegated stone, doubtless, is yonder sun: it is thus yonder sun that is set up. It is variegated, for by means of its rays that disk is variegated. He sets it up between the Âhavanîya and the Gârhapatya; for the Gârhapatya is this (terrestrial) world, and the Âhavanîya is the sky: he thus places him (the sun) between these two worlds, whence he shines between these two worlds.