Jaiminīya (Talavakāra) Brāhmaṇa 1.27

1.27

sa tato reṣmāṇameva rathaṃ samāsthāyādityasya salokatāmabhiprayāti
tryahaṃ juhoti
dvādaśāhutayassaṃpadyante
dvādaśa māsāssaṃvatsaraḥ
saṃvatsaro vā idaṃ sarvam
yadihāśnāti yatpibati yasmai kasmai cana prativyādadāti sarvaṃ tadasyānaśitaṃ
bhavati yāvajjīvānāśakavratī bhavati
eṣa vai mṛtyuryadādityo mrocanneva nāma
tameva tābhirāhutibhiśśamayitvā divaṃ lokānāṃ jayatyādityaṃ devaṃ devānām
ādityasya devasya sāyujyaṃ salokatāṃ samabhyārohati ya evaṃ vidvānagnihotraṃ
juhoti

Mounting the whirlwind as a chariot, he journeys from there toward co-existence with Āditya.
He offers for three days.
Twelve oblations are completed.
Twelve months are the year.
The year indeed is this all.
Whatever he eats here, whatever he drinks, to whomever he opens his mouth [to speak], all that becomes uneaten for him; he keeps the vow of fasting for as long as he lives.
This indeed is death, which is named Āditya the Setting One.
Having pacified him by means of those oblations, he conquers heaven among worlds, Āditya among gods.
He ascends to union, to co-existence with the god Āditya, who, knowing thus, offers the fire-offering.