Deuteronomy 4:24

Thy God is a consuming fire - They had seen him on the mount as an unconsuming fire, while appearing to Moses, and giving the law; and they had seen him as a consuming fire in the case of Korah, Dathan, Abiram, and their company. They had, therefore, every good to expect from his approbation, and every evil to dread from his displeasure.