is there any scripture/commentary that reconciles wildly different stories about the "birth" of Rudra?

Question

here are three I am aware of

(1) Shatapatha Brahmana - he is the son of Brahma's incestuous union with his daughter and is said to be born with sin right from birth

(2) Aitareya Brahmana - created from the anger/fear of Devas to punish Brahma for his incest

(3) Krishna bhagavatam Rudra was born from between Brahmā's eyes when Brahmā was very angry at the four Kumāras.

Answer 1

Reconciling becomes very easy if you replace the English word "birth" with the word "emergence". So when does Rudra emerge?

1. In Sukla Yajur Veda Śatapatha Brāhmaṇa as the "start of creation" Rudra emerged along with the fundamental elements from Prajapati's tapas like (water,clay,sand,stone,metals,Akṣarā/syllables/sounds). Here Rudra emerged and further expanded into 8 folds.
2. In Rig Veda Bhaskala Śākhā Kausitaki as the creation unfolded with the fundamental celestial phenomenon from Prajapati's yajna ( Agni, Vayu, Adityas, Chandrama, and Uṣas) and came forth Rudra with thousand eyes, feet, and weapons.
3. Vājasaneyi Saṃhitā Śatapatha Brahmāṇa also narrates an event where in Prajāpati’s tears of anguish and exhaustion, which are called Tapodhuma, cover the wrath of Manyu. This Manyu is the hundred-headed Rudra with a thousand eyes and thousands of weapons. The remaining three Vedas speak of this multifaceted form of Rudra as Viṣvarūpam.
4. Kṛṣṇa Yajur Veda that the final stage of the fire-altar becomes Rudra, also the remnant of the Yajñá becomes whole and so restarts the Yajñá itself.
5. Rudras and Maruts as Earth-shaking clans feared by all lokas and are the only Divinities feared greatly by Rishis/Rśi. Since the Vedas revolve around Yajñá, the aspect of fear is seen in the discipline, devotion, and secrecy of the Yajamana and Adhvaryu towards their Dikṣhā (initiation and sanctity), meaning the one hosting the Yajñá and the one performing/chanting the mantras in the proper order (Ardhaka), else Rudra Emerges brings forth His wrath and consumes them (Taittiriya Samhita)
6. Atharva Veda is very specific about Rudra emerging as the punisher and inflictor/slayer of Ardhaka,if they alters (altering) and is improper chants the mantras, and destroys those who do not-sacrifice/insulting Divinities. This is why oblations are given, requesting to pardon/spare towards the one hosting the Yagna.
7. Katha Āraṇyaka is also very specific aiming at the protection of the yajamāna else Rudra would emerge. The same applies also to other divinities who question the authority or refrain offerings to Rudra or fail to recognize him. This is why all divinities who ascended to the heavenly realm addressed Rudra as the Sarva. A priest (brahmana) who wants to spoil his own yajamāna for one reason or another just has to alter one syllable…. Even the smallest mistake in ritual might lead to disaster: if certain mantras would be said loudly, Rudra would emerge and kill the yajamāna’s cattle.

Why Rudra should emerge? After reading the above we should pose more serious questions, we know Rudra punishes those who perform improper Yagna, and since Agni is the Hotr/the priest, and Agni is the Vedic Speech, Agni is the sacrificial fire, and Agni is the one who takes the Sacrifice of Yajna, then what does Rudra do with this sacrifice? Well, we might say Rudra is the Lord of that sacrifice and the lord of all Hymns, so Rudra receives all the sacrifice of Yagna and all the Vedic mantras, but wait, isn’t Rudra the one who receives the remnant of the sacrifice? Yes, in many cases so that he can restart the Yagna treating the remnant as a whole. What about Soma, does He receive it and compete for Soma like Indra and others? No, Rudra is already conjoined with Soma. Then will Rudra distribute this sacrifice? Will Rudra decide what the Yajamana (Owner of Yajna) will receive? Well one might say, Rudra is Agni and Agni is Rudra and they both are the same, if so, then why does Agni become Rudra? Rather the correct question is, why does Rudra manifest in Agni? We asked a lot of serious questions so let’s see what Rig Veda and Yajur Veda has to say:

gātha-patim = Rudra the resort to all hymns/songs; medha-patim = Rudra the resort of Yajñá/Sacrifice/Oblations RV 1.43

Thou, Oh Agni, art Rudra, the Asura of the mighty sky, Rudra, lord of the sacrifice TS 1.3.14/1.4.11

कथा महे पुष्टिम्भराय पूष्णे कद्रुद्राय सुमखाय हविर्दे kathā́ mahé puṣṭimbharā́ya pūṣṇé b kád rudrā́ya súmakhāya havirdé To the great Pushan () bestower of abundane, and to that Rudra (कद्रुद्राय = kád+Rudra), the high-sprited/energitic (सुमख) distributer of sacrifice (हविर्दे). RV4.3.7

कद्धिष्ण्यासु वृधसानो अग्ने कद्वाताय प्रतवसे शुभंये परिज्मने नासत्याय क्षे ब्रवः कदग्ने रुद्राय नृघ्ने RV 4.3.6 kád dhíṣṇyāsu vr̥dhasānó agne kád vātāya prátavase śubhaṁyé párijmane nā́satyāya kṣé brávaḥ kád agne rudrā́ya nr̥ghné Oh Agni (अग्ने) we implore, blazing hight (वृधसान) from the dhíṣṇyā side of the Yajna alter, with powerful force (प्रतवस्) like wind (द्वात ) added to fire (कद्वाताय = kád+vātā +ya, ) lifing/raising up (शुभंया), encompassing the ground and surrounding the fire-alter/or Earth (परिज्मन् क्षे), what shall you (कदग्ने = kád+agne) say/tell to the dreadfull punisher (नृघ्ने) Rudra (of those who have perfomed improper Yagna/chant and who is the distributer of havis/sacrifice RV4.3.7). Please note: कद्वाताय = adding stong wind, in this case its to fire. Similar to पश्चाद्वात = winds blowing to the west side.

Mahābhārata Itihāsam Section 285: Thou art the beginning and thou art the end of the Vedas, thou art the Gāyatri and thou art OM. Thou art the fire upon which the sacrificial butter/ghee is poured. Thou art he who pours the ghee. Thou art he in honor of whom the ghee is poured, thou art the butter itself that is poured. Thou art those section of Brahmanas that are called Trisuparna, thou art all the Vedas, thou art the section called Śatarudrīya in the Yajushes/Yajur. Thou art holiest of holies, auspicious of auspicious things. Thou animates the inanimate body. Thou art the Chit that dwell in the human form.

Mahābhāratam Moksha Dharma Parva Section 285 Vyasa said”, ‘Hearing these words of the lotus-born Brahma, Maheswara became gratified. Desirous of extending his grace, he laughed aloud. The celestials then gratified (with praise) both Uma and Rudra. The arm of the thunder-wielding Sakra re-got its natural state. That foremost one of all the gods, that destroyer of Daksha’s sacrifice, that divine lord having the bull for his sign, became gratified with the gods. He is Rudra he is Siva, he is Agni, he is everything, and he hath knowledge of everything. He is Indra, he is the Wind, he is the twin Aswins, and he is the lighting. He is Bhava, he is Parjanya, he is Mahadeva, he is sinless. He is the Moon, he is Isana, he is Surya, he is Varuna. He is Kala, he is Antaka, he is Mrityu, he is Yama. 1 He is the day, and he is the night. He is the fortnight, he is the month, he is the seasons. He is the morning and evening-twilights, he is the year. He is Dhatri, he is Vidhatri, he is the Soul of the universe, and he is the doer of all acts in the universe. Though himself without body, it is he who is the embodied celestial.

Mahābhāratam Drona Parva Section 202-203 (jaya section) Sri Krishna says to Yudhishthira about Rudra: Brāhmanas conversant with the Vedas says that the divine has two forms. One of these is terrible, and the other mild and auspicious. Those two forms, again, are subdivided into many forms3. That form which is fierce and terrible is regarded as identical with Agni, and Lightening (Asani), and Surya. That other from which is mild and auspicious is identical with Righteousness and Water and Chandramas4. Then again, it is said that half of his body is fire and half is Soma (or the moon).

Mahābhāratam Anuśāsanica Parva Section 161 (non-jaya section)

Mahābhāratam Dharma Parva Section 285 (Jaya section) concurs with this by saying “Thou art the beginning and thou art the end of the Vedas, thou art the Gāyatri and thou art OM”.

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