The Gayatri Mantra is the most hallowed mantra of the Vedas. It is considered the "mother of all the mantras“
Aum bhur bhuvah svah
tat savitur varenyam
bhargo devasya dhimahi
dhiyo yo nah pracodayat
We meditate on the transcendental glory of the Deity Supreme, who is inside the heart of the earth, inside the life of the sky and inside the soul of the Heaven. May He stimulate and illumine our minds.