29 And it came to pass, that at midnight the LORD smote all the firstborn in the land of Egypt, from the firstborn of Pharoah that sat on his throne unto the firstborn of the captive that was in the dungeon; and all the firstborn of cattle.
“He that has opened a pit and dug it.” We do not find the name of “pit” (lakkos) ever assigned in the divine Scriptures in the case of something good, nor a “well” of water (phrear) in the case of something bad. That into which Joseph was thrown by his brothers is a pit (lakkos). And there is a slaughter “from the firstborn of Pharaoh unto the firstborn of the captive woman that was in the prison (lakkos).”
[AD 379] Basil of Caesarea on Exodus 12:29