Thematic Bible: Natural rocks sometimes used as

So, Gideon, went in, and made ready a kid of the goats, and, of an ephah of meal, unleavened cakes, the flesh, he put in a basket, and, the broth, he put in a pot, - and brought them forth unto him, under the oak, and presented them. And the messenger of God said unto him - Take the flesh and the cakes, and set them on this crag, and, the broth, do thou pour out. And he did so. Then the messenger of Yahweh put forth the end of the staff, that was in his hand, and touched the flesh, and the cakes, - and there came up fire out of the rock, and consumed the flesh, and the cakes, and, the messenger of Yahweh, had departed out of his sight.

So Manoah took the kid, and the meal-offering, and caused them to ascend upon the rock unto Yahweh, who was about to do, wondrously, while Manoah and his wife were looking on. And it came to pass, when the flame ascended from off the altar, towards the heavens, that the messenger of Yahweh ascended in the flame of the altar, - while Manoah and his wife were looking on. Then fell they on their faces, to the earth.