Yahweh speaks of the houses of Jacob and Joseph as if they were fire because they will destroy Esau like a fire that quickly and completely burns up straw. (See: [[rc://en/ta/man/jit/figs-metaphor]])
The word "house" is a metonym for the family that lives in the house. In this case it refers to Esau's descendants. Alternate translation: "descendants of Esau" (See: [[rc://en/ta/man/jit/figs-metonymy]])