Shanti Mantras are hymns chanted for peace and harmony. Among those is the world famous mantra that goes as follows:-
ॐ सहनाववतु। सह नौ भुनक्तु। सह वीर्यं करवावहै। तेजस्विनावधीतमस्तु। मा विद्विषावहै।।
ॐ शांतिः शांतिः शांतिः।।
This mantra is from the Taittiriya Upanishad of the Krishna Yajurveda. It speaks about two entities who are part of actions together. It is often chanted at the beginning of teaching or auspicious events.
The key word for understanding this hymn is the word नौ , another form of आवाम् meaning "both of us".
The word सह means "together".
So the first phrase सहनाववतु means "May both of us be protected together".
Next step is nourishment. Derived from the root भुज् (bhuj), the word भुनक्तु signifies nourishment. So सह नौ भुनक्तु means, "May both of us be nourished together".
Next is action. वीर्यं here signifies energy.
सह वीर्यं करवावहै therefore means, "May both of us act with energy and vigor".
The result of our actions is what comes next.
अधीतं means "achievement" here. So तेजस्वि नौ अधीतम् अस्तु signifes, "May what we achieve be bright and fill us with brilliance".
Now arises a chance of conflict which is addressed in the next part.
मा विद्विषावहै means "May there be no conflict among us".
The final words ॐ शांतिः शांतिः शांतिः mean, "May there be peace inside us, in the nature and in the universe."