Why Even the Lowly Maidservant's Firstborn Died

"And to the firstborn of the maidservant" (Exodus 11:5). Rav Huna and Rabbi Aha in the name of Rabbi Eleazar son of Rabbi Yose the Galilean: Even the maidservants chained to the millstones used to say, We desire our enslavement of Israel, and Israel in their enslavement. Rabbi Yudah ben Pazi said: It is a tradition of aggadah that when Serah went down to Egypt she was chained to the millstones. [The reference to Serah is preserved in the manuscript tradition though its full sense is uncertain.]