Bhagavad Gita 18.38 Chapter 18, Verse 38

विषयेन्द्रियसंयोगाद्यत्तदग्रेऽमृतोपमम् ।
परिणामे विषमिव तत्सुखं राजसं स्मृतम् ॥१८.३८॥

viṣayendriyasaṃyogādyattadagre'mṛtopamam
pariṇāme viṣamiva tatsukhaṃ rājasaṃ smṛtam

Meaning

Happiness that arises from contact of the senses with their objects, which is like nectar at first but like poison in the end, is considered rajasic.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 18.38 (Chapter 18, Liberation through Renunciation (Moksha Sannyasa Yoga), Verse 38)