Manava Dharmashastra 4.6

4.6

naivaṃ mantavyaṃ satyānṛtobhayarūpatā śāstreṇa vāṇijye'bhyanujñāyata iti | kiṃtarhi vastusvabhāvavādo'yam | lobhaprahaṇamevānṛtam |
jīvyata itivacanādvāṇijyā jīvanāyaiva, na dhanasañcayāya |
sevā śvavṛttiḥ yathā hi śvā preryate, kṛcchreṇa ca labhate, tathā ca sevakaḥ | ‘sevā’ preṣyatvam | yatrakutracitkarmaṇi preṣyate, ucite'nucite vā, sa sevakaḥ | ata utkṛṣṭenāyudhakarmādinā ye rājānamupasarpanti te na śvavṛttayaḥ |

Trade is “Truth and Falsehood;” even by that one may live. Service has been declared, to be the “living of dogs;” hence one should avoid it.—(6)

Medhātithi’s commentary (manubhāṣya):
It should not be understood that the scripture here lays down the fact of Trade being both ‘true’ and ‘false;’ it only describes the nature of the thing; and what constitutes the ‘falsehood’ of Trade is the element of avaricious grabbing involved in it.

‘May live.’—This implies that Trade may be had recourse to, only for the purposes of livelihood, never for that of accumulating wealth.

‘Service is the living of the dog.’—The dog is made to work hard, and gets little and with difficulty; so also the servant. ‘Service’ here connotes being ordered about; the servant is always commanded to do this and that work, right as well as wrong. Hence, when people serve kings with such superior kind of work as the carrying of arms and the like, these are not regarded ‘as the living of dogs,’—(6)