That the created world is illusory is the default fundamental theme of the Vedanta. The Bhagavatam is a repository of instances that demonstrate this phenomenon. Here is one such instance where the display of māyā is presented in the Markandeya episode:
श्रीमद्भागवतपुराणम्/स्कन्धः १२/अध्यायः ९
अथाप्यम्बुजपत्राक्ष पुण्यश्लोकशिखामणे ।द्रक्ष्ये मायां यया लोकः सपालो वेद सद्भिदाम् ॥ ६ ॥
O lotus-eyed Lord, O crest jewel of renowned personalities, although I am satisfied simply by seeing You, I do wish to see Your illusory potency, by whose influence the entire world, together with its ruling demigods, considers reality to be materially variegated.
Rshi Markandeya requests Bhagavan to show him the
māyā power. This request is akin to Arjuna making a similar plea to the Lord in the Bhagavad gita 1th chapter.
Not only there is a different world apart from Brahman, the different gods too are non-different from Brahman.
The chapter there is a description of such a display. What indeed is māyā? It is the power that makes the homogeneous One appear as many. This is nothing but the vivarta of Advaita.
Sridhara Swamin comments for the word sadbhidām of the above verse as: सद्भिदां = सति वस्तुनि भेदम् (Sat is Brahman. Perception of bheda, difference, in that Sat.)
What comes to mind upon hearing of the above display is the Mahabharata instance:
‘माया ह्येषा मया सृष्टा यन्मां पश्यसि नारद ।’ (म. भा. १२ । ३३९ । ४५) ‘सर्वभूतगुणैर्युक्तं नैवं मां ज्ञातुमर्हसि’ (म. भा. १२ । ३३९ । ४६) इति ॥ १७ ॥
where Narayana himself reveals to Narada his Vishwarupa and calls it a display of his maayaa. Bhagavan adds: You should not know Me to be someone attributed by such a creation. In other words the Lord is clarifying - Do not know Me, Brahman, as something endowed with creation.
लीनप्रकृतिनैर्गुण्यादलिंगत्वादसम्भवः ॥३१॥
"Free from sorrow through the attainment of Brahman, with doubts (delusion of) about duality cut away, Absorbed in the quality-less state of nature, Formless and thus beyond birth."
Sridhara Swamin's commentary:
ज्ञानफलमाह विशोक इति । एतदेव शोकहेत्वभावेनोपपादयति शोकस्य हि हेतु: द्वैतभ्रमस्तस्य देहस्तस्य लिंगं तस्य गुणास्तेषामविद्या । तत्र ब्रह्मसंपत्स्या वेदान्तश्रवणेन ब्रह्माहमिति ज्ञानेन लीना प्रकृतिरविद्या यस्मिंस्तन्नैर्गुण्यं भवति, न तु सुषुप्तिप्रलययोरिवाविद्याशेषः । तस्मान्नैर्गुण्याद् गुणकार्यलिंगनाशः । अलिंगत्वाच्चासंभवः सम्यग्भोगाय भवति पुनः पुनरिति संभवः स्थूलदेहस्तद्रहितस्ततश्च तत्परिच्छेदाभावात्संच्छिन्नो द्वैवलक्षणः संशयो भ्रमो यस्य स विशोको जात इति ।। ३१ ।। *
अभिधानरत्नमाला This dictionary/lexicon gives the meaning 'bhrama' for 'shanka'.
शङ्का
शङ्का, वितर्क, सन्देह, संशय, आरेक, विभ्रम, विचिकित्सा, विकल्प, भ्रान्ति
शङ्का वितर्कः सन्देहः संशयारेकविभ्रमाः ।
विचिकित्सा विकल्पश्च भ्रान्तिरेकार्थवाचकाः ॥ ६९१ ॥
verse 4.1.1.691
page 0080
Bhishma's Advaitic realization
In the Srimad Bhagavatam, 1st Canto, Chapter 9, Bhishma, in his last moments, does a stuti of Sri Krishna and finally says:
तमिममहमजं शरीरभाजां
हृदि हृदि धिष्ठितमात्मकल्पितानाम् ।
प्रतिदृशमिव नैकधार्कमेकं
समधिगतोऽस्मि विधूतभेदमोह: ॥ ४२ ॥
I have realized that Supreme who is present in each and every manas of the beings which Brahman has created. It is akin to one sun appearing as many in the various reflecting bodies. So too One Atman alone exists and the perception of apparent multiplicity is due to delusion, from which I am now free.
The delusion, 'bheda moha', is stated in the Vishnu Purana too:
सर्वभूतान्यभेदेन ददृशे स तदात्मनः ।
यथा ब्रह्मपरो मुक्तिमवाप परमां द्विजः ॥ २,१६.२० ॥
तथा त्वमपि धर्मज्ञ तुल्यात्मरिपुबान्धवः ।
भव सर्गगतं जानन्नात्मानमवनीपते ॥ २,१६.२१ ॥
सितनीलादिभेदेन यथैकं दृश्यते नभः ।
भ्रान्तदृष्टिभिरात्मापि तथैकः सन्पृथक्पृथक् ॥ २,१६.२२ ॥
एकः समस्तं यदिहास्ति किञ्चित्तदच्युतो नास्ति परं ततोन्यत् ।
सोऽहं स च त्वं च सर्वमेतदात्मस्वरूपं त्यज भेदमोहम् ॥ २,१६.२३ ॥
'Just as that Brahmana attained liberation owing to his perceiving everything as non-different from the Self, thereby tuned to Brahman, you too, O King, knower of Dharma, looking upon yourself, enemies and relatives as the same, knowing the One Atman to be present in all. The wrong perception of many Atmans is due to delusion, as exemplified in the space/sky appearing as many owing to the erroneous perception of colours such as white, black, etc. even though space is one only without any colours. Whatever exists is only that Supreme Achyuta and nothing else other than That exists. All perception of duality as 'I am that, you are that, he is' etc. are all due to ignorance which you give up.
Thus, the māyāvāda of Veda Vyasa is a fine endorsement of Advaita. What is shown above is only a sample. There are many such unambiguous statements across the Vedavyasa corpus.
The Māyāpanchakam of Shankaracharya:
That the Upanishads are the basis for the Māyāvāda of Vedavyāsa can be appreciated by a cursory look into the various Upanishadic statements Shankara has cited in his Bhashyas to bring out this very phenomenon of .'The One alone appearing as the many.' In fact this premise is underlying the other premise of the Upanishads: Eka-vijnānena sarva-vijnānam. Without the former premise, the latter premise can't be stated.
warm regards