A Convocation address in Ancient India

Chapter XI—Exhortation to the Departing Student
1

Having taught the Vedas, the teacher thus instructs the pupil:
Speak the truth. Practise dharma. Do not neglect the study of the Vedas. Having brought to the teacher the gift desired by him, enter the householder's life and see that the line of progeny is not cut off. Do not swerve from the truth. Do not swerve from dharma. Do not neglect personal welfare. Do not neglect prosperity. Do not neglect the study and teaching of the Vedas.

2

Do not neglect your duties to the gods and the Manes. Treat your mother as God. Treat your father as God. Treat your teacher as God. Treat your guest as God. Whatever deeds are faultless, these are to be performed—not others. Whatever good works have been performed by us, those should be performed by you—not others.

3

Those brahmins who are superior to us—you should comfort them by giving them seats.
Whatever is to be given should be given with faith, not without faith—according to one’s plenty, with modesty, with fear, with sympathy.

4

Now, if there arises in your mind any doubt concerning any act, or any doubt concerning conduct, you should conduct yourself in such matters as brahmins would conduct themselves—brahmins who are competent to judge, who of their own accord are devoted to good deed and are not urged to their performance by others, and who are not too severe, but are lovers of dharma.
Now, with regards to persons spoken against, you should conduct yourself in such a way as brahmins would conduct themselves—brahmins who are competent to judge, who of their own accord are devoted to good deeds and are not urged to their performance by others, and who are not too severe, but are lovers of dharma.
This is the rule. This is the teaching. This is the secret wisdom of the Vedas. This is the command of God.
This you should observe. This alone should be observed.



Please see the link here for the above. Note that I have only given part of the Siksha Valli of the Taittirya Upanishad. The above address has the Upanishad in its entirety.