Devibhagavatapurana 3.29.34

3.29.34

mṛtā cejjānakī vīra prāṇāṃstyakṣyāmyasaṃśayam |
mṛtā cedasitāpāṅgīṃ kiṃ me dehena lakṣmaṇa ||

O Laksmana! And when Jânakî sacrifices her life, I will assuredly do the same; for, of what use, then is this body to me when that fair Sîtâ has gone away with her life?”