to set on fire: to kindle a blaze that consumes something
This verb is about igniting a fire, the moment something is set alight and begins to burn. In the historical books it is what an army does to a captured town: soldiers put the city, its gate, or a field to the torch. That destructive edge stays with the word wherever it goes.
Most often the one lighting the fire is God, especially in the oracles of Jeremiah, where the same phrase recurs like a refrain: I will kindle a fire in her gates, her forest, her cities, and it will not be put out. Here the fire is an image of unstoppable judgment. The word also runs the other direction, describing the aftermath: cities and pastures left burned, or laid in ashes, with no one living in them.
Because fire is such a natural picture for anger, the word can also describe wrath itself flaring up. When Scripture says the LORD's fury was kindled, it borrows the language of a blaze catching and spreading.