Jaiminīya (Talavakāra) Brāhmaṇa 2-8.432

2-8.432

athaiṣa vaiśvānaraḥ prāyaṇīyo'tirātraḥ
tasyaiṣordhvā kḷhipta svargyā
tasya rathantaraṃ pṛṣṭhaṃ bhavati vāmadevyaṃ maitrāvaruṇasāma bṛhadārbhave pavamāne
idaṃ vai rathantaramantarikṣaṃ vāmadevyamada eva bṛhat
saiṣordhvā kḷhipta svargyā
tayā haitayā kḷhaptyordhvaṃ svargaṃ lokaṃ rohanti
atho haiṣāmetadeva sāma kḷhaptaṃ kṛtsnaṃ yuktaṃ yajñaṃ vahati

Now this introductory Atirātra belongs to Vaiśvānara. Its ascending arrangement is heavenly. Its pṛṣṭha is the Rathantara; the Vāmadevya is the Maitrāvaruṇa sāman; the Bṛhat is in the Ārbhava Pavamāna. This Rathantara is this [earth]; the Vāmadevya is the atmosphere; that Bṛhat is yonder [sky]. This is the ascending arrangement that leads to heaven. By this arrangement they ascend up to the heavenly world. Moreover, this arranged, complete, yoked sāman bears their sacrifice.