en_tn_condensed/isa/05/24.md

tongue of fire

"flame of fire" or "flame"

as the tongue of fire devours stubble, and as the dry grass goes down in flame

These phrases mean basically the same thing. God will punish the people described in Isaiah 5:18-23. Alternate translation: "as a fire burns up stubble and grass" (See: rc://en/ta/man/translate/figs-parallelism and rc://en/ta/man/translate/figs-simile)

stubble

The dry pieces of plants that are left in the ground after the stalks have been cut.

their root will rot, and their blossom will blow away like dust

Isaiah speaks of these people as if they were a dying plant. Alternate translation: "they will die like a plant whose roots have rotted and whose blossom has dried up and blown away in the wind" (See: rc://en/ta/man/translate/figs-metaphor)