Here is part of the opening verse of the Taittiriya Upanishad.
tvam eva pratyaksham brahmāsi
tvam eva pratyaksham brahma vadisyāmi
tad vaktāram avatu
Aum Sānti Santi SAntiH
Salutations to the Wind.
Thou indeed are the perceptible Brahman.
Of Thou as the perceptible Brahman, I will speak.
I will speak of that which is right.
I will speak of that which is true.
May it protect me!
May it protect him that speaks.
Om, peace! peace! peace!
This invocation sees in the wind (air: an absolute essential for life) a material manifestation of Brahman, the sustainer of all life. It makes a promise to utter only that which is morally right, and to speak of only that which is the truth. In other words, this is a resolution to engage only in moral discourse, and also never to speak of anything that is untrue. It seeks the protection of the Divine, not only for the aspirant but for all who are committed to moral uprightness and to the truth.