Avigayil Halpern wrote:

In a stunning Senior Sermon, my friend Rabbi Mary Brett Koplen... points out that in the verses about the Plague of the Firstborn, the Torah makes visible a figure we would otherwise not have noticed.

וַיֹּאמֶר מֹשֶׁה כֹּה אָמַר ה כַּחֲצֹת הַלַּיְלָה אֲנִי יוֹצֵא בְּתוֹךְ מִצְרָיִם׃ וּמֵת כׇּל־בְּכוֹר בְּאֶרֶץ מִצְרַיִם מִבְּכוֹר פַּרְעֹה הַיֹּשֵׁב עַל־כִּסְאוֹ עַד בְּכוֹר הַשִּׁפְחָה אֲשֶׁר אַחַר הָרֵחָיִם וְכֹל בְּכוֹר בְּהֵמָה׃

Moses said, “Thus says the LORD: Toward midnight I will go forth among the Egyptians, and every first-born in the land of Egypt shall die, from the first-born of Pharaoh who sits on his throne to the first-born of the slave girl who is behind the millstones; and all the first-born of the cattle.”

Koplen moves our focus to the enslaved Egyptian woman “who is behind the millstones.” She points out that this woman, like the Israelites, was marginalized and enslaved in Egypt.

If we ever thought we were the only slaves in Egypt, if we ever thought we were the only people who have ever suffered unjustly, Exodus 11:5 comes to teach us gently, we were wrong...

What can we gather from the text's need to separate Hebrew slaves from other slaves, and at the same time to tell us that the other slaves suffered along with those who were deemed to be worthy of that suffering? 

We also have other mentions in the Exodus story of the "Eirev Rav," which has been translated as the "mixed multitude" of people who left Egypt along with the Hebrews (Exod 12:38). Several scholars have identified this group as either Egyptian slaves, or descendents and community members who created families with Hebrews but were not themselves Hebrews. Were these the same people? Were they moved to join in the Exodus even after their first born children were killed in the plague? How closely tied are grief and solidarity? 

haggadah Section: -- Ten Plagues