Every Upanishad commences with a prayer, the Shanti Mantra; a formula for the invocation of peace, chanted at the beginning and close of study. The Shanti Mantra of the Katha Upanishad reads:
auṁ saha nāvavatu, sahanau bhunaktu, saha vīryam karavāvahai,
tejasvi nav adhītam astu: mā vidviṣāvahai; auṁ śāntih, śāntih, śāntih.
It means that there should be proper attunement of spirit between the Guru and disciple before they begin the study, for only then will the teaching be fruitful: “May we both be protected. May both of us be taken care of properly. May we study together. May our teaching and learning be resplendent. May there be no misunderstanding between us. May there be no discord of any kind. May there be peace, may there be peace, may there be peace.” Thrice peace; we have three kinds of troubles, called tapatraya: internally, physical ones; externally, from outside beings; and from above, given by the gods. May all these cease.