While reading these accounts, I remembered that the first time I heard of an extra person being with people in trouble was the biblical story found in Daniel 3 of the three men thrown into the fiery furnace. Not only did they survive sure death, but onlookers noticed a fourth person in the furnace with them. Here's one version of that story:

  ¹⁹ Then Nebuchadnezzar was furious with Shadrach, Meshach and Abednego, and his attitude toward them changed. He ordered the furnace heated seven times hotter than usual ²⁰ and commanded some of the strongest soldiers in his army to tie up Shadrach, Meshach and Abednego and throw them into the blazing furnace. ²¹ So these men, wearing their robes, trousers, turbans and other clothes, were bound and thrown into the blazing furnace. ²² The king's command was so urgent and the furnace so hot that the flames of the fire killed the soldiers who took up Shadrach, Meshach and Abednego, ²³ and these three men, firmly tied, fell into the blazing furnace.

  ²⁴ Then King Nebuchadnezzar leaped to his feet in amazement and asked his advisers, "Weren't there three men that we tied up and threw into the fire?"

      They replied, "Certainly, O king."

  ²⁵ He said, "Look! I see four men walking around in the fire, unbound and unharmed, and the fourth looks like a son of the gods."