Describing how a brahmin should earn his livelihood, Lord Brahma said to Narada–Alms, which a brahmin gets without making any demand for it, is called Vritta. ‘Unchhavritti’ is even better than Vritti and it means collecting foodgrain which are scattered in places like fields, granary, market-place etc. A brahmin should accept the Dakshaina that his host gives him after the completion of yagya ceremony. He should engage himself in educational activities. He can also earn his livelihood by engaging himself in other auspicious activities.
If the circumstances do not permit a brahmin to earn his livelihood by any of the above mentioned means, then he may opt for the occupation of a kshatriya. In such a case, he should endeavor to have mastery both over the vedas as well as different weaponary. Battle should be his last option. When the very existence of religiousness is at stake, he should wage a war against irreligious people and to protect the religion.
In an emergency situation, a brahmin can also choose the occupation of a Vaishya and earn his livelihood by doing business or agriculture. But, while earning his livelihood by doing agriculture, he should in no circumstances abandon his own duties (duties of a brahmin). He should be honest while doing business and never try to exploit the customers.