“vēdaśabdēbhya ēvādau nirmimītē sa īśvaraḥ| Even the great rishis and their names pre-exist in Vedas and later on when they take birth, their names are assigned as per the blue-print present in Vedas. He clearly states that entire universe including its mobile and immobile creation takes its form and shape from the blue prints which are hidden in Vedas. The Mokshadharmanusasana Parva which is an upa-parva of Santi-Parva of Mahabharata, has a discourse by Vyasa about the creation of Universe. From him alone all these were breathed forth”. “As clouds of smoke proceed by themselves out of a lighted fire kindled with damp fuel, thus, verily, O Maitreyî, has been breathed forth from this great Being what we have as Rig-veda, Yagur-veda, Sama-veda, Atharvâṅgirasas, Itihâsa (legends), Purâna (cosmogonies), Vidyâ (knowledge), the Upanishads, Slokas (verses), Sûtras (prose rules), Anuvyâkhyânas (glosses), Vyâkhyânas (commentaries). “sa yathārdraidhāgner abhyāhitāt pṛthag dhūmā viniścaranty eva vā are ‘sya mahato bhūtasya niḥśvasitam etad yad ṛgvedo yajurvedaḥ sāmavedo ‘tharvāṅgirasa itihāsaḥ purāṇaṃ vidyā upaniṣadaḥ ślokāḥ sūtrāṇy anuvyākhyānāni vyākhyānani | asyaivaitāni niśvasitāni ||” (Brihadaranyaka Upanishad 2:4:10) Vaikhari Vak works through the medium of breath, hence here the breath of the Parameshwara is said to be the origin of the Vedas. In other words, it is the vaikhari Vak of the Supreme Being which pronounced the Vedas out. What it actually means is – from the Vak of the Supreme lord, manifested all these Vedas. Now, it doesn’t mean to say what it literally says. It says that Vedas (and all scriptures) have sprang forth from the mouth of the Supreme Being via his breath.

The Brihadaranyaka Upanishad which is a part of Satapatha Brahmana of Yajur Veda tells us how the Vedas and other scriptures manifested.

Dakshinamurti suta samhita