Vishnupurana 3.8.37

3.8.37

āśramāṇāṃ ca sarveṣām ete sāmānyalakṣaṇāḥ
guṇāṃs tathāpaddharmāṃś ca viprādīnām imāñ chṛṇu //

"Besides these their respective obligations, there are duties equally incumbent upon all the four castes. These are, the acquisition of property, for the support of their families; cohabitation with their wives, for the sake of progeny; tenderness towards all creatures, patience, humility, truth, purity, contentment, decency of decoration, gentleness of speech, friendliness; and freedom from envy and repining, from avarice, and from detraction. These also are the duties of every condition of life.

"In times of distress the peculiar functions of the castes may be modified, as you shall hear. A Brahman may follow the occupations of a Kshatriya or a Vaiśya; the Kshatriya may adopt those of the Vaiśya; and the Vaiśya those of the Kshatriya: but these two last should never descend to the functions of the Śúdra, if it be possible to avoid them; and if that be not possible, they must at least shun the functions of the mined castes. I will now, Rájá, relate to you the duties of the several Ásramas or conditions of life."