SB 10.85.44
idam ittham iti prayas
tava yogesvaresvara
na vidanty api yogesa
yoga-mayam kuto vayam
Translation:
What to speak of ourselves, O Lord of all perfect yogis, 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 svarupa, or essential identity, and also its visesas, the attributes that make it different from other things. Maya, the energy underlying all material existence, is more subtle than ordinary phenomena. Only God and His liberated devotees, therefore, can know its svarupa and visesa.