The Torah's description of the tenth plague contains a phrase that seems redundant but actually expands the scope of the devastation far beyond Egypt's borders: "and I smote every firstborn" (Exodus 12:29). The Mekhilta reads this as meaning even firstborns who were not physically in Egypt that night.
The question is straightforward. An Egyptian firstborn who happened to be traveling abroad — visiting Canaan, trading in Phoenicia, stationed with a garrison in Nubia — was that person safe? Did geography provide a shield against the plague?
The Mekhilta says no. "Even from different places" — the plague reached Egyptian firstborns wherever they were. The proof comes from (Psalms 136:10): "He smote Egypt through their firstborn." The Psalmist does not say "He smote Egypt's firstborn in Egypt." He says He smote Egypt through their firstborn, wherever those firstborn happened to be. The plague followed the bloodline, not the border.
This teaching radically expands what happened on the night of the Exodus. It was not a localized catastrophe confined to the Nile Valley. It was a global event, touching every Egyptian firstborn on the face of the earth simultaneously. No distance was far enough. No escape route was fast enough. When God declared judgment on Egypt, He meant all of Egypt — not just the territory but the people, down to the last firstborn son stationed at the farthest outpost of Egyptian power.
The theological message is stark. God's justice is not limited by geography. When He acts, the whole world is His jurisdiction. There is no place outside His reach.