Bhagavad Gita Chapter 18.38
viṣayendriya-saḿyogād
yat tad agre ’mṛtopamam
pariṇāme viṣam iva
tat sukhaḿ rājasaḿ 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.