28 And the children of Israel went away, and did as the Lord had commanded Moses and Aaron, so did they. 29 And it came to pass, that at midnight the Lord smote all the firstborn in the land of Egypt, from the firstborn of Pharaoh that sat on his throne unto the firstborn of the captive that was in the dungeon; and all the firstborn of cattle. 30 And Pharaoh rose up in the night, he, and all his servants, and all the Egyptians; and there was a great cry in Egypt; for there was not a house where there was not one dead.
The Israelites obeyed Moses’s word. We will see many other instances where they did not, but here they did exercise the faith necessary to be preserved from destruction, and so it was only the Egyptian firstborn who met their fate that night. The manner of the Egyptians’ deaths is not described, but perhaps it was not silent, for we are told that their families were awoken in the middle of the night and discovered what God had done.
Verse 30 reinforces the totality of this night of destruction: “there was not a house where there was not one dead.” The word used for “house” is bayith, which is sometimes used to mean a “household.” That meaning makes more sense to me, as presumably there could have been a dwelling place that had no firstborn sleeping within its walls, but every “household” would have had a complete family unit with a firstborn who had perished.
Thus, every life in Egypt was touched that night. Each person either died, or lost a close family member. This was an act of great surgical precision by God, taking a minimum number of lives, yet ensuring that everyone would have their heart broken at once. Where human acts of conquest tend to be broad and imprecise, with all manner of collateral damage, God was able to take just what He meant to take, and leave the rest untouched.