What exactly is meant in Saṅkara (Advaita) Vedānta when it declares that Brahman is Nirguṇa (attributeless)?

Question

From this answer where it explains about Brahman being Nirguṇa & Guṇas (attributes) appearing due to Avidyā, the ācārya writes,

तदेवमविद्यात्मकोपाधिपरिच्छेदापेक्षमेवेश्वरस्येश्वरत्वं सर्वज्ञत्वं सर्वशक्तित्वं च, न परमार्थो विद्यया अपास्तसर्वपाधिस्वरुपे आत्मनि ईशत्रीशितव्यसर्वज्ञत्वादिव्यवहार उपपद्यते, तथा चोक्तम् - 'यत्र नान्यपश्यति नान्यच्छृणोति नान्यद्विजानाति स भूमा इति' यत्र 'त्वस्य सर्वमात्मैवाभूत्तत्केन कं पश्येत्' इत्यादिना च एव परमार्थवस्थायां सर्वव्यवहाराभावं वदन्ति वेदान्ता ।। 2.1.14
Hence the Lord's being a Lord, his omniscience, his omnipotence, &c. all depend on the limitation due to the adjuncts whose Self is Avidya; while in reality none of these qualities belong to the Self whose true nature is cleared, by right knowledge, from all adjuncts whatever. 

Now, positing Guṇas appearing due to Māyā implies Guṇas were inherently present in Brahman, in latent form, which appears due to Avīdyā. If it were not so, then it would imply that existence sprung out from non-existence? rendering it inconsistent with Chānḍogya Upaniṣada 6,

2. “The Existent was here in the beginning, my son, alone and without a second. On this there are some who say, ‘The Nonexistent was here in the beginning, alone and without a second. From that Nonexistent sprang the Existent.’ “But how could it really be so, my son?” he said. “How could what exists spring from what does not exist? On the contrary, my son, the Existent was here in the beginning, alone and without a second.

Wherefore end up expositing existence couldn't sprung from non-existence. It makes me wonder—

• How all these Guṇas sprung forth out of Nirguṇa Brahman presuming Nirguṇa means attributeless?
• Or is it the case that Nirguṇa Brahman is endowed with all the Guṇas in latent form?
  i.e, Claiming Brahman to be Nirguṇa actually means that the Brahman consists of all Guṇas while simultaneously surpassing them (panentheistic Brahman?), which doesn't leave Brahman confined to a particular Guṇa anymore, thus rendering Brahman fully Nirguṇa?

So, what's the definition of Nirguṇa according to Advaita Vedānta if the world with its Guṇas sprung forth from Nirguṇa Brahman?

Answer 1

My question is - saying Gunas/attributes/qualities appear due to Māyā clearly implies Gunas were present in Brahman in latent form which appears clearly due to Avīdyā, if it not so then it would mean that existence sprung out from non existence?

One of the fundamental concepts in Advaita Vedanta is "Mithya". While there is no correct translation into English, the closest is "Relative Reality". "Satyam" on the other hand is "Absolute Reality".

The three states of awareness - waking, dream, deep-sleep - are all Mithya. Most people realize easily that the dream state is Mithya, because it's not available during the waking state. However, when you are in the dream, it appears real. Note that the Advaitin does not negate the experience, only the absoluteness of that reality. Similarly, the waking state is not available in the dream or deep sleep states, and therefore is not Absolute Reality. Only Brahman, which permeates and transcends the three states is Absolute Reality, or Satyam.

Now, getting to your question, the Attributes/Gunas are also Mithya or ASat. (sorry - I don't know how to put the fancy characters up). Only Satyam is Absolute Existence; all Mithya is Relative Existence. The attributes are "relatively-existent", but not "absolutely-existent". Therefore, existence has NOT sprung from non-existence.

Answer 2

Brahman is described in the upanishads

“Brahman is Existence, Consciousness, Infinitude.” —Taitt. Up., II. 1.

“Brahman is Consciousness, Bliss.” —Brih. Up., III. 9. 28.

Satchidananda is the svarupa lakshana of Brahman. Just like heat is the svarupa lakshana of fire. It is an attribute external but inherent to it. Therefore, if Brahman is eternal, Sat Chit Ananda must also be eternal. According to Shankara, you cannot split up Sat-Chit-Ananda into three separate entities, just as you cannot separate light, heat and luminosity from fire.

Just as luminosity is the nature of the Sun, coolness of water and heat of fire, so too the nature of the Atman is Eternity, Purity, Reality, Consciousness and Bliss. Atma Bodha 24

We cannot deny our own existence. Thus, we never were not existent and that we never will cease to be existent (even though our physical bodies may disappear) clearly proves that Atman always exists. Atman is Chit for it shines by itself unaided by any other light and illumines the whole universe by its own light. Just as we cannot deny existence, so also we cannot deny consciousness.

Sat, Chit and Ananda are one. Atman is partless and homogeneous. The three characteristics Sat, Chit and Ananda are not distinct from one another. When there is existence, there has to be consciousness. When there is only one, there is no fear of two and thus there is bliss.

"Where there is neither seeing nor hearing nor knowing of anything else which is a second entity—that is the Infinite [bliss]” (Chh. Up., VII. 23, 24).

Hence whatever is manifested, viz. this universe, is the Supreme Brahman Itself, the Real (Sat), the One without a second, pure, the Essence of Knowledge (Chit), taintless, serene, devoid of beginning and end, beyond activity, the Essence of Bliss Absolute (Ananda) transcending all the diversities created by Maya or Nescience, eternal, ever beyond the reach of pain, indivisible, immeasurable, formless, undifferentiated, nameless, immutable, self-luminous. Vivekachudamani 237-238

Answer 3

Attempting to answer from whatever I understood so far! Note, I am not dragging 3 truths theory because I have yet to find it in works of Ādi Śaṅkarāchārya.

The Māyā is power of Brahman & it created the world. Nirguṇa Brahman is actually Brahman baring its power called Māyā. In other words, Nirguṇa Brahman is unmodified Brahman. From Vivekāchuḍāmaṇī,

108. Avidya (Nescience) or Māyā, called also the Undifferentiated, is the power of the Lord. She is without beginning, is made up of the three Guṇas and is superior to the effects (as their cause). She is to be inferred by one of clear intellect only from the effects She produces. It is She who brings forth this whole universe. - Verse 108

And Ādi Śaṅkarāchārya implictely called Nirguṇa Brahman an unmodified Brahman in its commentary of the aforementioned verse of the Chāndogya Upaniṣada as,

hence it only right to assert that before birth, it was being only; especially because every form of the product is only a modification based upon words.,

Therefore, Nirguṇa in Nirguṇa Brahman connotes to unmodification. It's the power of Brahman (which is identical to the Brahman), called Māyā, that creates. As an analogy, the Sun alone is Nirguṇa Brahman; the Sun with its rays is Nirguṇa Brahman with its power Māyā and it's only the rays that travel to light the corners of the world, not the Sun itself (It's Māyā that creates the world) yet the rays remain identical to the Sun all this while. Ādi Śaṅkarāchārya gave the same analogy in his Ātmabodha,

The body, senses, mind, and buddhi engage in their respective activities with the help of consciousness, which is inherent in Ātman, just as the men work with the help of the light that is inherent in the sun. - verse 19

For a final nail in coffin, from Ādi Śaṅkarāchārya,

O! Bhagavati! Only if Parama Siva is enjoined with You, the Sakti, He is empowered to create. The same Lord is indeed powerless even to move sans Thy company. O! Mother, the celebrities such as Hari, Hara and Brahma and others, ever worship Thee. In such a context, how can one (I) be capable of saluting or praising you without the meritorious effects of (my) yester deeds? - Soundarya Lahirī-1

Here, Paramśiva is Brahman with its power Māyā or Bhāgvatī or Śaktī! rest conforms & conduces to whatever I've explained already.

Then, the questions can be answered with the explanation & references attested above,

How all these Guṇas sprung forth out of Nirguṇa Brahman presuming Nirguṇa means attributeless?

These guṇas sprung forth out of power of Brahman, called Māyā. When Brahman is asserted as Nirguṇa, it's asserted so on virtue of it being transcendental. Power of Brahman brings about guṇas, not Brahman itself without power (which is Nirguṇa Brahman) as evident from Only if Parama Siva is enjoined with You, the Sakti, He is empowered to create. The same Lord is indeed powerless even to move sans Thy company.

Or is it the case that Nirguṇa Brahman is endowed with all the Guṇas in latent form? i.e, Claiming Brahman to be Nirguṇa actually means that the Brahman consists of all Guṇas while simultaneously surpassing them (panentheistic Brahman?), which doesn't leave Brahman confined to a particular Guṇa anymore, thus rendering Brahman fully Nirguṇa?

It's more of semantics. When Nirguṇa Brahman is described to be Nirguṇa, it connotes to transcendental Brahman baring its power called Māyā, then it can be said that Nirguṇa Brahman isn't actually endowed with guṇas but its power called Māyā is. Therefore, attributes are latent in power of Brahman & Brahman surpasses its power rendering it Nirguṇa.

P.S: Taking another analogy, when we see dreams, our subjective being-ness remains transcendental to the dreams that are creations of the mind. We remained trasnscendental to the dreams because our existence isn't confined to the mind alone that has created the dreams— our existence has more to it beyond manomaye koŚa. Similarly, Brahman remains transcendental to the attributes of its power because Brahman has power & isn't mere power but more than it.