Who volunteered going into prison?
When Moshe warned Pharaoh about the impending Makkas Bechoros it says that all firstborn will die from the firstborn of Pharaoh who sits on his throne to the firstborn of the maidservant who is behind the millstone (11:5). However, later on when describing the unfolding of the plague we find from the firstborn of Pharaoh sitting on his throne to the firstborn of the captive who was in the dungeon (12:29). Why the change from the maidservant who is behind the millstone to the captive who was in the dungeon?
The Chizkuni offers two other approaches to reconcile the pesukim:
When the word spread that HaShem had warned that He would strike the firstborn from the firstborn of Paroh who sits on his throne to the firstborn of the maidservant, some reasoned that the captives in the dungeon are on a lower level than that of the maidservant. They mistakenly concluded that prisoners are excluded from Makkas Bechoros, and they placed themselves in the dungeon in order to be spared from the plague. However, the Torah testifies that even the firstborn who placed themselves in prison out of their own free will, also were subject to Makkas Bechoros.
Alternatively, when the non-Jewish slave s heard that the fate of their masters was equal to their fate, they had a level of satisfaction, knowing that they were not discriminated against due to their low status in Egypt. As a result of expressing this feeling, their masters were furious with them and placed them in the dungeon. Thus, the pasuk is describing where the non-Jewish slaves were at the time of Makkas Bechoros, namely in the dungeon.
Which Jewish people were allowed to leave their house at the night of Makkas Bechoros?
Although it clearly states “and as for you, you should not leave the entrance of the house until morning” (12:22), that only applied to Jewish men. Jewish ladies and children were allowed to leave the house (and for this reason the pasuk uses the word - a man- to exclude ladies and children [Panim Yafos, see there that the ladies went and requested gold, silver, and clothing from the Egyptians during this night].
Additionally, the simple meaning of the text states that after Makkas Bechoras Pharaoh summoned Moshe and Aharon to appear in front of him in his palace, which they did. This must mean that Moshe and Aharon went out of their houses on that night on HaShem's instructions (Ibn Ezra).
