Isaiah 5:24

The flame "The tongue of fire" - "The flame, because it is in the shape of a tongue; and so it is called metaphorically." Sal. ben Melec. The metaphor is so exceedingly obvious, as well as beautiful, that one may wonder that it has not been more frequently used. Virgil very elegantly intimates, rather than expresses, the image; -

Ecce levis summo de vertice visus Iuli

Fundere lumen apex; tactuque innoxia molli

Lambere flamma comas, et circum tempora pasci