Aitareyabrahmana 2.33: adhyāya 10, khaṇḍaḥ 1-9

2.33

brahma vā āhāvaḥ, kṣatraṃ nivid, viṭ sūktam.
āhivayate 'tha nividaṃ dadhāti, brahmaṇy eva tat kṣatram anuniyunakti.
nividaṃ śastvā sūktaṃ śaṃsati. kṣatraṃ vai nivid viṭ sūktaṃ,
kṣatra eva tad viśam anuniyunakti
yaṃ kāmayeta: kṣatreṇainaṃ vyardhayānīti,
madhya etasyai nividaḥ sūktaṃ śaṃset. kṣatraṃ vai nivid viṭ sūktaṃ,
kṣatreṇaivainaṃ tad vyardhayati
yaṃ kāmayeta: viśainaṃ vyardhayānīti,
madhya etasya sūktasya nividaṃ śaṃset. kṣatraṃ vai nivid viṭ sūktaṃ,
viśaivainaṃ tad vyardhayati
yam u kāmayeta: sarvam evāsya yathāpūrvam ṛju kḷptaṃ syād ity,
āhvayetātha nividaṃ dadhyād atha sūktaṃ śaṃset. so sarvasya kḷptiḥ
Prajāpatir vā idam eka evāgra āsa. so 'kāmayata:
prajāyeya bhūyān syām iti.
sa tapo 'tapyata, sa vācam ayachat,
sa saṃvatsarasya parastād vyāharad dvādaśakṛtvo.
dvādaśapadā vā eṣā nivid, etāṃ vāva tāṃ nividaṃ vyāharat,
tām sarvāṇi bhūtāny anvasṛjyanta
tad etad ṛṣiḥ paśyann abhyanūvāca:
sa pūrvayā nividā kavyatāyor imāḥ prajā ajanayan manūnām iti
tad yad etām purastāt sūktasya nividaṃ dadhāti, prajātyai
prajāyate prajayā paśubhir ya evaṃ veda

ii. 33 (x. 1). The call is the holy power, the Nivid the lordly power, the hymn the people; he calls, then he inserts the Nivid; verily thus he makes the lordly power dependent on the holy power. Having inserted the Nivid he recites the hymn; the Nivid is the lordly power, the hymn the people; verily, thus he makes the people dependent on the lordly power. If he desire of a man, 'Let me deprive him of the lordly power,' he should recite the hymn in the middle of the Nivid; the Nivid is the lordly power, the hymn the people; verily thus he deprives him of the lordly power. If he desire of a man, 'Let me deprive him of the people,' he should recite a Nivid in the middle of the hymn; the Nivid is the lordly power, the hymn the people; verily thus he deprives him of the people. But if he desire of a man 'May all be in due and proper order and correct for him,' he should call, then insert the Nivid, and then recite the hymn. Thus is the ordering of all. Prajāpati was here being one only in the beginning. He desired 'May I be propagated and become greater'; he practised fervour; he restrained speech; at the end of the year he uttered twelve times. The Nivid has twelve clauses; it was just the Nivid that he uttered; after it were all beings created. Beholding this the seer declares —

'He at the call aforetime of Āyu with his wisdom
Brought into being these sons of man.'

In that he inserts the Nivid before the hymn (it serves) for propagation; he is propagated with offspring, with cattle who knows thus.