इन्द्रियाणि मनो बुद्धिरस्याधिष्ठानमुच्यते।एतैर्विमोहयत्येष ज्ञानमावृत्य देहिनम्॥
indriyāṇi mano buddhir asyādhiṣṭhānam ucyateetair vimohayatyeṣa jñānam āvṛtya dehinam
Word by word
The verse says
The senses, the mind and the understanding are where it lives. Working through those, it clouds what a person knows and fools the one inside.
In plain words
Krishna locates it. Three addresses.
Senses. Mind. Buddhi - the discerning faculty itself.
That last one is the alarming item on the list. Desire does not only grab your appetites. It gets into the equipment you would use to evaluate it.
Where you've felt this · in study
You want the answer to be yes, so the reasons for yes are the ones that occur to you first. Nobody is lying to anybody. The search itself was quietly weighted before it started.
Going deeper
Desire is not loose in the system. It has an address.
Adhiṣṭhāna - seat, dwelling place, base of operations. The military sense of the word is not accidental in a chapter that has just named this an enemy.
The list runs outward to inward, and the third entry is the one that matters. If kāma occupied only the senses, you could think your way out. If it occupies the buddhi, the instrument of judgement is compromised, and the compromise will not show up in the judgements.
That is why the advice here is not reason with it. You cannot audit a system from inside the part that has been captured.
The verb is strong - it thoroughly deludes - and what it deludes is the embodied one, the dweller in the body from 2.13. The thing being fooled is not the machinery. It is whoever is riding in it.
Which is what makes the next verse sound the way it does. Krishna does not say understand this. He says kill it, and he says start at the outermost ring.