Here the second phrase about the "firstfruits" is used to describe the "firstborn" in the first phrase. Alternate translation: "He killed every firstborn in their land, which were the firstfruits of all their strength" or "Then Yahweh killed the oldest son in every house of the people of Egypt" (See: [[rc://en/ta/man/jit/figs-parallelism]] and [[rc://en/ta/man/jit/figs-metaphor]])