Speech and words spoken in a language the speaker does not know, inspired by God in the form of the Holy Spirit.

Referenced in the Christian Bible in Acts 2 :1-4
"When the day of Pentecost came, they all had met in one room. Suddenly they heard what sounded like a powerful wind from heaven, the noise of which filled the entire house in which they were staying. Then the tongues of fire appeared to them and, as they separated, they came to rest on the head of each of them. They were all filled with the Holy Spirit, and began to speak foreign languages as the Spirit prompted them."

And in the story of the Tower of Babel in Genesis 11:1-9:
1 Now the whole Earth used the same language and the same words.
2 And it came about as they journeyed east, that they found a plain in the land of Shinar and settled there.
3 And they said to one another, "Come, let us make bricks and burn them thoroughly." And they used brick for stone, and they used tar for mortar.
4 And they said, "Come, let us build for ourselves a city, and a tower whose top will reach into heaven, and let us make for ourselves a name; lest we be scattered abroad over the face of the whole earth."
5 And the LORD came down to see the city and the tower which the sons of men had built.
6 And the LORD said, "Behold, they are one people, and they all have the same language. And this is what they began to do, and now nothing which they purpose to do will be impossible for them."
7 "Come, let Us go down and there confuse their language, that they may not understand one another's speech."
8 So the LORD scattered them abroad from there over the face of the whole earth; and they stopped building the city.
9 Therefore its name was called Babel, because there the LORD confused the language of the whole earth; and from there the LORD scattered them abroad over the face of the whole earth.