Skandapurana 2.9.20.120

2.9.20.120

iti śrīskānde mahāpurāṇa ekāśītisāhasryāṃ saṃhitāyāṃ dvitīye vaiṣṇavakhaṇḍe śrīvāsudevamāhātmye cāturvarṇyadharmanirūpaṇaṃ nāma viṃśo'dhyāyaḥ ..20..

Thus ends the twentieth chapter, entitled 'Determination of the Duties of the Four Classes', in the Vāsudevamāhātmya of the second, Vaiṣṇavakhaṇḍa, in the glorious Skanda Mahāpurāṇa, a collection of eighty-one thousand [verses]. (20)