Mbh 3.221.1a

Markandeya continued, “Mudita, the favourite wife of the fire Swaha, used to live in water. And Swaha who was the regent of the earth and sky beget in that wife of his a highly sacred fire called Advanta. There is a tradition amongst learned Brahmanas that this fire is the ruler and inner soul of all creatures. He is worshipful, resplendent and the lord of all the great Bhutas here. And that fire, under the name of Grihapati, is ever worshipped at all sacrifices and conveys all the oblations that are made in this world. That great son of Swaha--the great Adbhuta fire is the soul of the waters and the prince and regent of the sky and the lord of everything great. His (son), the Bharata fire, consumes the dead bodies of all creatures. His first Kratu is known as Niyata at the performance of the Agnishtoma sacrifice. That powerful prime fire (Swaha) is always missed by the gods, because when he sees Niyata approaching him he hides himself in the sea from fear of contamination. Searching for him in every direction, the gods could not (once) find him out and on beholding Atharvan the fire said to him, ‘O valiant being, do thou carry the oblations for the gods! I am disabled from want of strength. Attaining the state of the red-eyed fire, do thou condescend to do me this favour!’ Having thus advised Atharvan, the fire went away to some other place. But his place of concealment was divulged by the finny tribe. Upon them the fire pronounced this curse in anger, ‘You shall be the food of all creatures in various ways.’ And then that carrier of oblations spoke unto Atharvan (as before). Though entreated by the gods, he did not agree to continue carrying their oblations. He then became insensible and instantly gave up the ghost. And leaving his material body, he entered into the bowels of the earth. Coming into contact with the earth, he created the different metals.