Vishnupurana 1.15.139

1.15.139

yathā sūryasya maitreya udayāstamanāv iha
evaṃ devanikāyās te saṃbhavanti yuge yuge //

These classes of thirty-three divinities are born again at the end of a thousand ages, according to their own pleasure; and their appearance and disappearance is here spoken of as birth and death: but, Maitreya, these divine personages exist age after age in the same manner as the sun sets and rises again.