Aitareyabrahmana 5.31

5.31

udyann u khalu vā Āditya āhavanīyena raśmīn saṃdadhāti.
sa yo 'nudite juhoti,
yathā kumārāya vā vatsāya vājātāya stanam pratidadhyāt tādṛk tad.
atha ya udite juhoti,
yathā kumārāya vā vatsāya vā jātāya stanam pratidadhyāt tādṛk tat.
tam asmai pratidhīyamānam ubhayor lokayor annādyam anu pratidhīyate
'smāc ca lokād amuṣmac cobhābhyāṃ
sa yo 'nudite juhoti,
yathā puruṣāya vā hastine vāprayate hasta ādadhyāt tādrik tad.
atha ya udite juhoti,
yathā puruṣāya vā hastine vā prayate hasta ādadhyāt tādṛk tat.
tam eṣa etenaiva hastenordhvaṃ hṛtvā svarge loka ādadhāti
ya evaṃ vidvān udite juhoti.
tasmād udite hotavyam
udyann u khalu vā Ādityaḥ sarvāṇi bhūtāni praṇayati,
tasmād enam prāṇa ity ācakṣate.
prāṇe hāsya samprati hutam bhavati ya evaṃ vidvān udite juhoti.
tasmād udite hotavyam
eṣa ha vai satyaṃ vadan satye juhoti,
yo 'stamite sāyaṃ juhoty udite prātar.
bhūr bhuvaḥ svar o+m Agnir jyotir jyotir Agnir iti sāyaṃ juhoti,
bhūr bhuvaḥ svar o+ṃ Sūryo jyotir jyotiḥ Sūrya iti prātaḥ.
satyaṃ hāsya vadataḥ satye hutam bhavati ya evaṃ vidvān udite juhoti.
tasmād udite hotavyaṃ
tad eṣābhi yajñagāthā gīyate
pratāḥ-prātar anṛtaṃ te vadanti
purodayāj juhvati ye 'gnihotram \
divā kīrtyam adivā kīrtayantaḥ
Sūryo jyotir na tadā jyotir eṣām
iti

v. 31 (xxv. 6) Āditya on rising unites his rays with the Āhavanīya; if one offers before sunrise, that is as if one were to offer the breast to a child unborn or to a calf unborn. But, if he offers after sunrise, that is as if one were to offer the breast to a child born or a calf born. Through his being united in both worlds proper food is offered both from this world and from yonder to him. If he offers before sunrise, that is as if one were to offer to a man or an elephant, without hand stretched out , if he offers after sunrise it is as if one were to offer to a man or an elephant, with hand stretched forth. He having taken him with his hand and dragged him upwards places him in the world of heaven, who knowing thus offers after sunrise. Therefore one should offer after sunrise. Āditya as he rises leads forward all creatures; therefore they call him breath. In breath does he sacrifice who knowing thus sacrifices after sunrise; therefore one should sacrifice after sunrise. Speaking truth he offers in truth who offers in the evening after sunset and in the morning after sunrise. With _bhūḥ, bhuvaḥ, svar, om_; Agni is light, light is Agni' he offers in the evening; with '_bhūḥ, bhuvaḥ, svar, om_; Sūrya is light, light is Sūrya' in the morning. By him speaking truth in truth is the offering made, who knowing thus offers after sunrise; therefore should one offer after sunrise. As to this a sacrificial verse is sung:

‘Every morning they tell falsehood Who offer the Agnihotra before sunrise, Declaring what is to be declared by day on what is not day, “Sūrya is the light”; there is not then light for them.’