Mbh 12.221.6

"'Bhishma said, "He will be regarded as one that is always fasting if he eats once during the day and once during the night at the fixed hours without eating anything during the interval. Such a Brahmana, by always speaking the truth and by adhering always to wisdom, and by going to his wife only in her season and never at other times, becomes a Brahmacharin (celibate). By never eating meat of animals not killed for sacrifice, he will become a strict vegetarian. By always becoming charitable he will become ever pure, and by abstaining from sleep during the day he will become one that is always wakeful. Know, O Yudhishthira, that that man who eats only after having fed his servants and guests becomes an eater always of ambrosia. That Brahmana who never eats till gods and guests are fed, wins, by such abstention, heaven itself. He is said to subsist upon sacrificial remnants, who eats only what remains after feeding the gods, the Pitris, servants, and guests. Such men win numberless regions of felicity in next life. To their homes come, with Brahman himself, the gods and the Apsaras. They who share their food with the deities and the Pitris pass their days in constant happiness with their sons and grandsons and at last, leaving off this body, attain to a very high end."'"