Mahabharata Anushasna Parva Chapter 141:5

Mahabharata Anushasna Parva (Dana Dharma Parva) Chapter 141:5 Verily, the Sudra, who having got a guest, discharges the duties of hospitality towards him, is regarded as acquiring the merit of high penances. That intelligent Sudra whose conduct is righteous and who worships the deities and Brahmanas, becomes endued with the desirable rewards of righteousness. O beautiful lady, I have thus recited to thee what the duties are of the four orders. Indeed, O blessed lady, I have told thee what their respective duties are. What else dost thou wish to hear?" 'Uma said, "Thou has recited to me what the respective duties are of the four orders, auspicious and beneficial for them. Do thou now tell me, O holy one, what the common duties are of all the orders." 'Maheswara said, "The foremost of all beings in the universe viz., the Creator Brahma, ever desirous of righteous accomplishments, created the Brahmanas for rescuing all the worlds. Among all created beings, they are, verily, gods on earth. I shall at the outset tell thee what the religious acts are which they should do and what the rewards are which they win through them. That religion which has been ordained for the Brahmanas is the foremost of all religions. For the sake of the righteousness of the world, three religions were created by the Self-born One. Whenever the world is created (or re-created), those religions are created by the Grandsire. Do thou listen. These are the three eternal religions. The religion that is propounded in the Vedas is the highest; that which is propounded in the Smritis is the next in the order of importance; the third in importance is that which is based upon the practices of those who are regarded as righteous. The Brahmans possessed of learning should have the three Vedas. He should never make the study of the Vedas (or recitation of the scriptures) the means of his living.[] He should devote himself to the three well-known acts (of making gifts, studying the Vedas, and performing sacrifices). He should transcend the three (viz., lust, wrath, and covetousness). He should be the friend of all creatures. A person that possesses these attributes is called a Brahmana. The lord of the universe declared these six acts for the observance of Brahmanas. Listen to those eternal duties. The performance of sacrifices, officiating at the sacrifices of others, the making of gifts, the acceptance of gifts, teaching, and study, are the six acts by accomplishing which a Brahmans wins religious merit. Verily, the daily study of the Vedas is a duty. Sacrifice is (another) eternal duty. The making of gifts according to the measure of his power and agreeable to the ordinance, is, in his case, much applauded. Tranquillity of mind is a high duty that has always been current among them that are righteous. Householders of pure mind are capable of earning very great merit. Indeed, he who cleanses his soul by the performance of the five sacrifices, who is truthful in speech, who is free from malice, who makes gifts, who treats with hospitality and honour all regenerate guests, who lives in well-cleaned abodes, who is free from pride, who is always sincere in his dealings, who uses sweet and assuring words towards others, who takes pleasure in serving guests and others arrived at his abode, and who eats the food that remains after the requirements have been gratified of all the members of his family and dependants, wins great merit.