Vaisesika Sūtras
Vaisesika Sūtra 6.2.11
सुखाद् रागः ॥११॥
sukhād rāgaḥ ॥11॥
[सुखात् (sukhāt) - from pleasure; रागः (rāgaḥ) - attachment;]
Attachment arises from pleasure.