Vayupurana 2.17.73

Vāyupurāṇa 2.17.73

vyāpādanaṃ śaktinibarhaṇaṃ kṛṣirvāṇijyakāryyaṃ paśupālanaṃ ca.
śuśrūṣaṇaṃ vāpyaguro raho vā kāryyaṃ naitadvidyate brāhmaṇasya .. 17.71 ..