Bhagavad Gita Bhasya (Gambhirananada)

3.38 Yatha, as; vahnih, fire, which is naturally
bright; avriyate, is enveloped; dhumena, by smoke,
which is born concomitantly (with fire) and is
naturally dark; or as adarsah, a mirror; is covered
malena, by dirt; ca, and; garbhah, a foetus; is
avrtah, enclosed; ulbena, in the womb by the
amnion; tatha, so; is idam, this; avrtam, shrouded;
tena, by that. Again, what is that which is indicated
by the word idam (this), and which is covered by
desire? The answer is:
3.39 O son of Kunti, Knowledge is covered by this
constant enemy of the wise in the form of desire,
which is an insatiable fire.
English Translation of Sri Sankaracharya's Sanskrit
Commentary - Swami Gambhirananda
3.39 Jnanam, Knowledge; is avrtam, covered; etena,
by this; nityavairina, constant enemy; jnaninah, of
the wise. For the wise person knows even earlier, 'I
am being induced by this into evil.' And he always
[Both at the time when desire arises in him, and
also when he is forced to act by it.] feels distressed.
Therefore, it is the constant enemy of the wise but
not of a fool. For the fool looks upon desire as a
friend so long as hankering lasts. When sorrow
149