Altars: Natural Rocks Sometimes Used As

So Gideon went in and prepared a young goat and unleavened bread and an ephah of flour. He placed the meat in a basket and the broth in a pot and brought them out to present to Him under the oak. …

Then Manoah took a young goat and a grain offering and offered them on a rock to the LORD. And as Manoah and his wife looked on, the LORD did a marvelous thing.

When the flame went up from the altar to the sky, the angel of the LORD ascended in the flame. When Manoah and his wife saw this, they fell facedown to the ground.