Yahweh speaks of the descendantsof Jacob and Joseph as if they were fire because they will destroy the descendants of Esau like a fire that quickly and completely burns up straw. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Often "the house of Jacob" represents Israel, but here it represents only the people in the southern part of Israel. Joseph was one of Jacob's sons. Here "the house of Joseph" represents the people in the northern part of Israel.
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]])