Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 44

Sanskrit:

इदमित्थमिति प्रायस्तव योगेश्वरेश्वर ।न विदन्त्यपि योगेशा योगमायां कुतो वयम् ॥ ४४ ॥

ITRANS:

idam ittham iti prāyastava yogeśvareśvarana vidanty api yogeśāyoga-māyāṁ kuto vayam

Translation:

What to speak of ourselves, O Lord of all perfect yogīs, even the greatest mystics do not know what Your spiritual power of delusion is or how it acts.

Purport:

Systematic understanding of something should include knowledge of both its svarūpa, or essential identity, and also its viśeṣas, the attributes that make it different from other things. Māyā, the energy underlying all material existence, is more subtle than ordinary phenomena. Only God and His liberated devotees, therefore, can know its svarūpa and viśeṣa.