This material energy means the three modes of passion, ignorance and goodness. Tan-māyā-mohita. This is the moha. Moha means illusion.
Anyone who is contaminated by these three qualities of māyā, he is supposed to be involved in māyika . . . material existence. Tan-māyā-mohitatvād na jānanti: "And anyone who is involved with the material qualities of this external energy, they cannot understand what is God." It is not possible. Aviṣayatvāc ca. This is not their subject matter at all. The subject matter for them, different.
Therefore we see, they are becoming educated, scientists, philosophers, but they do not understand what is God. Avisayatvāc ca. It is not their subject matter. That I repeatedly say, that one who is not a devotee of Kṛṣṇa, it is . . . Bhagavad-gītā is not a subject matter for their study, what to speak of commenting upon it. He has no business to comment on Bhagavad-gītā, because it is not their subject matter. This should be very distinctly understood.