Thematic Bible: Natural rocks sometimes used as

And Gideon went in, and made ready a kid, and unleavened cakes of an ephah of flour: the flesh he put in a basket, and he put the broth in a pot, and brought it out to him under the oak, and presented it. And the angel of God said to him, Take the flesh and the unleavened cakes, and lay them upon this rock, and pour out the broth. And he did so. Then the angel of the LORD put forth the end of the staff that was in his hand, and touched the flesh and the unleavened cakes; and there rose fire out of the rock, and consumed the flesh and the unleavened cakes. Then the angel of the LORD departed from his sight.

So Manoah took a kid, with a meat-offering, and offered it upon a rock to the LORD; and the angel did wonderously, and Manoah and his wife looked on. For it came to pass, when the flame ascended towards heaven from off the altar, that the angel of the LORD ascended in the flame of the altar. And Manoah and his wife looked on it, and fell on their faces to the ground.