A Brahmana who knows (the sacred law) should shun at (sacrifices) both (to the gods and to the manes) these lowest of twice-born men, whose conduct is reprehensible, and who are unworthy (to sit) in the company (at a repast).
ब्राह्मणो त्वनधीयानस्तृणाग्निरिव शाम्यति । तस्मै हव्यं न दातव्यं न हि भस्मनि हूयते ॥ १६८ ॥
As a fire of dry grass is (unable to consume the offerings and is quickly) extinguished, even so (is it with) an unlearned Brahmana; sacrificial food must not be given to him, since it (would be) offered in ashes.
अपाङ्क्तदाने यो दातुर्भवत्यूर्ध्वं फलौदयः । दैवे हविषि पित्र्ये वा तं प्रवक्ष्याम्यशेषतः ॥ १६९ ॥
I will fully declare what result the giver obtains after death, if he gives food, destined for the gods or manes, to a man who is unworthy to sit in the company.
The Rakshasas, indeed, consume (the food) eaten by Brahmanas who have not fulfilled the vow of studentship, by a Parivettri and so forth, and by other men not admissible into the company.