धूमेनाव्रियते वह्निर्यथाऽऽदर्शो मलेन च।यथोल्बेनावृतो गर्भस्तथा तेनेदमावृतम्॥
dhūmenāvriyate vahnir yathādarśo malena cayatholbenāvṛto garbhas tathā tenedam āvṛtam
Word by word
The verse says
As smoke covers fire, as dust covers a mirror, as the womb covers what is growing in it — so this covers everything.
In plain words
Three images for one process, and they are not interchangeable.
Smoke over fire: thin, and it comes from the fire itself. Dust on a mirror: sits on the surface, wipes off. The womb around an embryo: total, and not a problem at all.
Krishna has graded the covering from light to complete.
Where you've felt this · in health
Some days it is a film you can see through. Some days it needs wiping off. Some days you are entirely inside it and there is no outside to notice from.
Going deeper
The three images are usually read as three ways of saying the same thing. They are not, and the sequence is the teaching.
Smoke is produced by the fire it obscures — the covering comes from the same source as the light. Dust is foreign, deposited from outside, and removable with an ordinary cloth. The caul around an embryo is neither foreign nor removable; it is constitutive, and the thing inside it has never known anything else.
So desire obscures in three different degrees, and the traditional reading maps them to how deeply a person is held.
The third image is the one that unsettles. An embryo is not being harmed by the membrane. It is being formed inside it, and cannot conceive of anything else. Applied to a mind, that describes a condition with no vantage point available from within.
And there is something gentler folded into the choice. None of the three coverings is evil. Smoke is a by-product. Dust is what happens to surfaces. A womb is how life is carried. The Gita is describing an obstruction, not an infestation.