Mahabharata 12.26.23

सुखस्यानन्तरं दुःखं दुःखस्यानन्तरं सुखम्न नित्यं लभते दुःखं न नित्यं लभते सुखम्

sukhasyānantaraṃ duḥkhaṃ duḥkhasyānantaraṃ sukhamna nityaṃ labhate duḥkhaṃ na nityaṃ labhate sukham

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