Here is the Sanskrit anuvad, Hindi anuvad, and English translation of Karma Yoga Chapter 3, Verse 3.38.
Sanskrit
धूमेनाव्रियते वह्निर्यथादर्शो मलेन च । यथोल्बेनावृतो गर्भस्तथा तेनेदमावृतम् ॥ ३.३८ ॥
Hindi
जिस प्रकार धूऍसे अग्नि और मैलसे दर्पण ढका जाता है तथा जिस प्रकार जेरसे गर्भ ढका रहता है, वैसे ही उस कामके द्वारा यह ज्ञान ढका रहता है|
English
Just as the smoke surrounds and covers a fire, just as dust surrounds and covers a mirror, and just as the amnion covers the embryo, similarly. Gyan or knowledge is covered and surrounded by one’s desires. O Arjuna.