Bhagavad Gita Chapter 3, Verse 34

इन्द्रियस्येन्द्रियस्यार्थे रागद्वेषौ व्यवस्थितौ | तयोर्न वशमागच्छेत्तौ ह्यस्य परिपन्थिनौ ||

indriyasyendriyasyārthe rāga-dveṣau vyavasthitau tayor na vaśam āgacchet tau hy asya paripanthinau

Attraction and aversion are situated in the senses toward their respective objects. One should not come under their control, for they are indeed one's enemies.

After teaching you to work with your nature (3.33), Krishna reveals the real enemies within that nature. The senses automatically develop rāga (attraction) and dveṣa (aversion) toward their objects—pleasant tastes, harsh sounds, comfortable situations, difficult tasks. This isn't wrong; it's vyavasthitau—built into how senses work. The danger comes when you let them control you. 'Tayor na vaśam āgacchet'—don't come under their power. These two are paripanthinau—your enemies disguised as preferences.