Shatapatha Brahmana 4.1.5.16

4.1.5.16

tau hocatuḥ | mukhyau vā āvāṃ yajñasya svo yāvadhvaryū iha nāvimam purastādgraham paryāharatābhi dvidevatyāniti tābhyāmetam purastādgraham paryājahrurabhi dvidevatyāṃstasmādeṣa daśamo graho gṛhyate tṛtīya eva vaṣaṭkriyate 'tha yadaśvināvitīme ha vai dyāvāpṛthivī pratyakṣamaśvināvime hīdaṃ sarvamāśnuvātām puṣkarasrajāvityagnirevāsyai puṣkaramādityo 'muṣyai

They said, 'Well, but we two, being the Adhvaryus, are the heads (leaders) of the sacrifice: transfer ye that graha of ours to this earlier time, to those belonging to two deities!' Accordingly they transferred that graha for them to a former time, to those belonging to two deities: hence that graha is drawn in the tenth place, and is consecrated by Vashat in the third place. And as to (the significance of) the Asvins,--the Asvins are manifestly those two, heaven and earth, for it is those two that have obtained possession of everything here;--'the lotus-crowned' they (the Asvins) are called: Agni, forsooth, is the lotus of this earth, and the sun that of yonder sky.