I answered it from the Gunas perspective since it is clear from the story of Hayagriva
Knowledge is the form of vedas when Madhu and Kaitabha stole them.
It can be understood better from Mahabharata itself.
I am listing the relevant paragraphs from Section 348 of Santi Parva of Mahabharata and the inferences in sequence to understand how do Vedas represent knowledge in this story.
The puissant Narayana, endued with infinity, is the supreme Lord and
Creator of the universe. He is the inner Soul of all things, and the
giver of boons. Divested of attributes, he is again possessed of them.
Listen now, O best of kings, to me as I narrate to thee how the
Destruction is brought about of all things. At first, the element of
Earth becomes merged in Water and nothing then is seen save one vast
expanse of Water on all sides. Water then merges into Heat, and Heat
into Wind. Wind then merges into Space, which in its turn, merges into
Mind. Mind merges into the Manifest (otherwise called Consciousness or
Ego). The Manifest merges into the Unmanifest (or Prakriti). The
Unmanifest (or Prakriti) merges into Purusha (Jivatman) and Purusha
merges into the Supreme Soul (or Brahman). Then Darkness spreads over
the face of the universe, and nothing can be perceived.
From that primal Darkness arises Brahma (endued with the principle of
Creation). Darkness is primeval and fraught with immortality. Brahma
that arises from primeval Darkness develops (by its own potency) into
the idea of the universe, and assumes the form of Purusha. Such
Purusha is called Aniruddha. Divested of sex, it is called otherwise
by the name of Pradhana (Supreme or Primary). That is also known by
the name of Manifest, or the combination of the triple attribute, O
best of kings. He exists with Knowledge alone for his companion.
Points need to be observed are
Aniruddha is manifested form of Narayana with three
gunas(attributes): sattva (goodness), rajas (passion), and tamas
Knowledge is the only companion to Aniruddha
Thus Aniruddha has sattva , rajas, tamas and knowledge.
That illustrious and puissant Being is otherwise called by the name of
Viswaksena or Hari. Yielding to Yoga-sleep, he lays himself down on
the waters. He then thinks of the Creation of the Universe of
diversified phenomena and fraught with immeasurable attributes. While
engaged in thinking of Creation, he recollects his own high
attributes. From this springs the four-faced Brahma representing the
Consciousness of Anirudha. The illustrious Brahma, otherwise called
Hiranyagarbha, is the Grandsire of all the worlds. Endued with eyes
like lotus petals, he takes birth within the Lotus that springs from
(the navel of) Anirudha. Seated on that Lotus, the illustrious,
puissant, and eternal Brahma of wonderful aspect saw that the waters
were on all sides. Adopting the attribute of Sattwa Brahma, otherwise
called Parameshthi, then commenced to create the universe. In the
primeval Lotus that was endued with the effulgence of the Sun, two
drops of water had been cast by Narayana that were fraught with great
merit. The illustrious Narayana, without beginning and without end,
and transcending destruction, cast his eyes on those two drops of
water. One of those two drops of water, of very beautiful and bright
form, looked like a drop of honey. From that drop sprang, at the
command of Narayana, a Daitya of the name of Madhu made up of the
attribute of Tamas (Dullness). The other drop of water within the
Lotus was very hard. From it sprang the Daitya Kaitabha made up of the
attribute of Rajas.
Points to be observed are
- Brahma exists in conscious form and is an embodiment of sattva guna only
- Madhu is tamas and Kaitabha is Rajas.
Thus Aniruddha becomes Brahma , Madhu, Kaitabha and knowledge.
We know that only sattva guna is capable to attain knowledge.
From the mode of goodness arises knowledge, from the mode of passion
arises greed, and from the mode of ignorance arise negligence and
[17, 14, Gita]
But if rajas and tamas are powerful enough, then it is impossible to get knowledge as they prevails over sattva
Sometimes goodness (sattva) prevails over passion (rajas) and
ignorance (tamas), O scion of Bharat. Sometimes passion (rajas)
dominates goodness (sattva) and ignorance (tamas), and at other times
ignorance (tamas) overcomes goodness (sattva) and passion (rajas).
[10, 14, Gita]
In our story, due to the mightiness of Madhu and Kaitabha, knowledge disappears.
Endued thus with the attributes of Tamas and Rajas, the two Daityas
possessed of might and armed with maces, immediately after their
birth, began to rove within that vast primeval Lotus. They beheld
within it Brahma of immeasurable effulgence, engaged in creating the
four Vedas, each endued with the most delightful form. Those two
foremost of Asuras, possessed of bodies, beholding the four Vedas,
suddenly seized them in the very sight of their Creator. The two
mighty Danavas, having seized the eternal Vedas, quickly dived into
the ocean of waters which they saw and proceeded to its bottom. Seeing
the Vedas forcibly taken away from him, Brahma became filled with
grief. Robbed of the Vedas in this way, Brahma then addressed the
Supreme Lord in these words.
You can notice that Madhu and Kaitabha seized Vedas. But, from where does the Vedas come from? It is the knowledge only. Because Aniruddha has only knowledge as companion along with his three attributes. And Brahma needs knowledge to create universe. If Rajas and Tamas seizes knowledge, then Brahma cannot able to carry on its task. And Brahma alone cannot reveal them again since sattva cannot get knowledge if rajas and tamas are also powerful enough. So, Brahma prayed for its knowledge and got it from Narayana.
Beholding the two foremost of Asuras prepared to do battle with him,
he (Hari) also set his mind to gratify that desire of theirs. Thereupon an
encounter took place between those two on one side and Narayana on the
other. The Asuras Madhu and Kaitabha were embodiments of the
attributes of Rajas and Tamas. Narayana slew them both for gratifying
Brahma. He thence came to be called by the name of Madhusudana (slayer
of Madhu). Having compassed the destruction of the two Asuras and
restored the Vedas to Brahma, the Supreme Being dispelled the grief of
Brahma. Aided then by Hari and assisted by the Vedas, Brahma created
all the worlds with their mobile and immobile creatures. After this,
Hari, granting unto the Grandsire intelligence of the foremost order
relating to the Creation, disappeared there and then for going to the
place he had come from.
Hari killed tamas and rajas and provided knowledge (Vedas) to Brahma to carry on the task of creation.
Note: Brahma in the first paragrah refers to parabrahman (Narayana) and not the creator Brahma.