Where is this prayer mentioned? I checked in Shanti Mantras of Upanishads but couldn't find reference
Sarve Bhavantu Sukhinah Sarve Santu Niramayah Sarve Bhadrani Pasyantu Ma Kaschid-Duhkha-Bhag-Bhavet
May all be happy; May all be free from disabilities; May all behold what is auspicious; May none suffer from sorrow.