Bhagavad Gita
2.62

ध्यायतो विषयान्पुंसः सङ्गस्तेषूपजायते | सङ्गात्सञ्जायते कामः कामात्क्रोधोऽभिजायते ||६२||

dhyāyato viṣhayān puṁsaḥ saṅgas teṣhūpajāyate saṅgāt sañjāyate kāmaḥ kāmāt krodho'bhijāyate

Translation

While contemplating the objects of the senses, a person develops attachment for them, and from such attachment desire arises, and from desire anger arises.

Interpretation

The chain of psychological degradation: contemplation of sense objects → attachment → desire → anger. The first step — dwelling mentally on the objects of the senses — is where the process begins. Every step follows inevitably from the last. This is why the Gita places such emphasis on where the mind rests, what it contemplates.