The Holy Night

One day a man went out in the dark night to borrow live coals to kindle a fire. He asked somebody for help, but his question was without an answer. He went away and at last he saw the gleam of a fire a long way off. Then he went in that direction and saw that the fire was burning in the open. A lot of sheep were sleeping around the fire, and an old shepherd sat and watched over the flock. He asked the shepherd for some coal – the shepherd didn’t mind about it. The man picked coals from the ashes with his bare hands, and laid them in his mantle. He didn't burn his hands when he touched them, nor did the coals scorch his mantle. The dogs tried to bite him, but their jaws and teeth didn’t obey them…
Who was the stranger? Read the story till the end to know it!