Mahabharata 3.223.4

सुखं सुखेनेह न जातु लभ्यं; दुःखेन साध्वी लभते सुखानिसा कृष्णमाराधय सौहृदेन; प्रेम्णा च नित्यं प्रतिकर्मणा च

sukhaṃ sukheneha na jātu labhyaṃ; duḥkhena sādhvī labhate sukhānisā kṛṣṇamārādhaya sauhṛdena; premṇā ca nityaṃ pratikarmaṇā ca

Our plain-language meaning of this verse is waiting for scholar review.