There is a story about the powerful Naaths of Datta Sampradaay.
One of the Naath in childhood was chanting this mantra as per his Gurus instructions. Some children came to him and requested him to help them make a human baby from clay or wet soil.
The child Naath helped them made a baby from clay but as He was chanting this mantra with dedication and feeling of samarpan or surrendering, the clay baby came to life. All children got panicked including the Naath and they all ran away. Later Naath's Guru adopted this child which came out of mantra miracle and established him as one of the Nine Navnaths.
Mantra is as below -
Om Tatsavitur Varenyam,
Urvarukmiv Bandhanaat Dhiyo Yo Naha Prachodayat.