Bhagavad Gita

ಧೂಮೇನಾವ್ರಿಯತೇ ವಹ್ನಿರ್ಯಥಾದರ್ಶೋ ಮಲೇನ ಚ ।
ಯಥೋಲ್ಬೇನಾವೃತೋ ಗರ್ಭಸ್ತಥಾ ತೇನೇದಮಾವೃತಮ್ ॥೩೮॥
dhūmenāvriyate vahniryathādarśo malena ca |
yatholbenāvṛto garbhastathā tenedamāvṛtam ||38||

Gist of the sloka:
Like smoke hides the fire [Lord], like dust covering the mirror [manas – mind], like the womb covering the fetus inside, Kama covers everything in people.
To give an example of how desire and anger, covers our eye, Lord Krishna gives a example here. The fire which brightens everything including itself, but when smoke covers it, it becomes difficult to see nor does it brighten the surroundings. The fire is like Lord, who brightens the universe. Whereas the Rajasic guna is like smoke. This comes in between us and the Lord preventing us from viewing the Lord. This action of the smoke is giving difficulties to the seeker who has Satvic qualities.
For people who have Rajasic qualities, the example given by Lord Krishna is about mirror. The mirror due to the Rajasic dust covering it cannot even view themselves clearly. They need to remove the action of the gunas with the bright light of knowledge - to get to truth.
For Tamasic people the example is about the fetus inside the womb. They are already in the dark. Even if the fetus opens the eye, it cannot see anything. It is already undergoing torture due to action of various water, mucus etc., They are unable to get out nor do anything about their situation. It is a trapped situation.
Without the deep desire to know about the Lord, these rajasic gunas continue to act and prevent us from realizing the truth.