Bhagavatapurana 4.14.45

4.14.45

taṃ tu te 'vanataṃ dīnaṃ kiṃ karomīti vādinam /
niṣīdety abruvaṃs tāta sa niṣādas tato 'bhavat //

45. He stood bending in a dejected and helpless condition saying, "What shall I do"; and they said to him, "Child, Nishīda (sit down)" ; so he became Nishāda (by race and profession.)