Material desire is undoubtedly the cause of the greatest unhappiness, and freedom from such desire is the cause of the greatest happiness. Therefore, completely cutting off her desire to enjoy so-called lovers, Piṅgalā very happily went to sleep.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
आशा हि परमं दुःखं नैराश्यं परमं सुखम् । यथा सञ्छिद्य कान्ताशां सुखं सुष्वाप पिङ्गला
āśā hi paramaṃ duḥkhaṃ nairāśyaṃ paramaṃ sukham | yathā sañchidya kāntāśāṃ sukhaṃ suṣvāpa piṅgalā
SB 11.8.44