RobH_en_tn/psa/105/036.md

He killed every firstborn in their land, the firstfruits of all their strength

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/translate/figs-parallelism and rc://en/ta/man/translate/figs-metaphor)