Manava Dharmashastra 4.6

4.6

satyānṛtaṃ tu vāṇijyaṃ tena caivāpi jīvyate
sevā śvavṛttir ākhyātā tasmāt tāṃ parivarjayet //

But trade and (money-lending) are Satyanrita, even by that one may subsist. Service is called Svavritti; therefore one should avoid it.