'Itself' in the Bible

And [after they] had passed the first and second guard, they came to the iron gate that leads to the city, which opened for them by itself, and they went out [and] went forward [along] one narrow street, and at once the angel departed from him.

And [when] Paul had gathered a large number of sticks and was placing [them] on the fire, a viper came out because of the heat [and] fastened itself on his hand.