We know from Torah that all B'nai Israel who:
- Ate the Passover lamb
- Did not eat leavening (bread and beer)
- Were inside at midnight (and stayed inside until morning)
- Were in a house whose doorposts were properly marked
were spared from the plague of the firstborn.
Their animals were also spared (it is not clear how, though the flocks would be too numerous to bring inside):
But to all the children of Israel, not one dog will whet its tongue against either man or beast, in order that you shall know that the Lord will separate between the Egyptians and between Israel. Exodus 11:7
We also know that non-Jews who did the above things and chose to take on the rules of Judaism (and were circumcised if male) were spared. Exodus 12:48-49
But what about Jews who were in Egypt but not able to go to a house and partake of the Passover meal?
Although the Hebrews lived in more of a serf-like state (keeping their own houses and communities and choosing their own family units), they were slaves in the sense that their lives did not belong to them. Pharaoh worked them any way he chose.
It follows that there would be Hebrews who worked in the palace, in the turquoise and copper mines of Serabit el-Khadim and Wadi Maghara (real mines of the era with archeological evidence), and possibly some others elsewhere.
What have commentators said about this, if anything? Or what can we assume? I can think of several possibilities:
- There were no Jews in the entire land of Egypt that were too far or not able to return to the Jewish community and eat the Passover meal with their family or someone else. This seems quite unlikely to me, but I haven't found evidence to the contrary. Edit: there are commentaries that speak of Jews being taken to tutor Egyptian children and perform other tasks away from their places of dwelling.
- These Jews were subject to the plague and many died.
- Moses was able to send messages and advise them of what to do ahead of time (there at least 2 weeks between the 9th and 10th plagues).
- Angels or other messengers of God told them what to do (or they had dreams or they "just knew").
- They were spared without following all or any of the rules.