Bhagavad-gītā 18.38
BG 18.38
Open the full passageविषयेन्द्रियसंयोगाद्यत्तदग्रेऽमृतोपमम् । परिणामे विषमिव तत्सुखं राजसं स्मृतम् ॥३८॥
Sanskrit
viṣayendriya-saṁyogād yat tad agre 'mṛtopamam pariṇāme viṣam iva tat sukhaṁ rājasaṁ smṛtam
Translation
That happiness which is derived from contact of the senses with their objects and which appears like nectar at first but poison at the end is said to be of the nature of passion.