BG Chap 18 - The natural activities of the brāhmaṇas

The activities of a brāhmaṇa are: controlling the mind and the external senses; austerity by accepting pains to the body prescribed by scripture; internal and external cleanliness; tolerance; honesty by being straight forward in all dealings; understanding the superior and inferior categories of existence from scripture; realizing the ultimate process defined in the scriptures; having firm faith in the truth presented in scriptures. The Supreme Lord Hari is to be understood by all the Vedas; He alone is the cause of everything; he is to be worshiped by prescribed actions; He is to be satisfied by devotion and a person should offer everything including himself to the Lord. These are the actions of the brāhmaṇa arising from his impressions. They might worship the devatās but with the understanding that they are the limbs of Viṣṇu, and not demand material benefits from them. The actions of the brāhmaṇas may arise occasionally in a kṣatriya or other varṇas with an increase of sattva, but they are mentioned in relation to a brāhmaṇa because of his predominance of sattva.