If a good Brahmana takes the food of one who lives by his learning. he is considered as taking the food of a Shudra. All good men should avoid such food.
विद्योपजीविनोऽन्नं च यो भुङ्क्ते साधुसम्मतः। तदप्यन्नं यथा शौद्रं तत् साधुः परिवर्जयेत्॥