Devibhagavatapurana 3.29.40

3.29.40

prāptavyaṃ sukhaduḥkhānāṃ bhogānnirvartanaṃ kvacit |
nānyathā jānakījāne tasmācchokaṃ tyajādhunā ||

O Darling of Jânakî! There must come a time when sorrows will be converted into happiness and vice versa; there will be nothing otherwise. So avoid this sorrow now and have firmness.