Q: Why didn’t Hagar, Sarah’s maidservant, become one of the mothers of the Jewish Nation, while Bilhah and Zilpah, the maidservants of Rachel and Leah, did become the mothers of four of the Tribes?
A: Bilhah and Zilpah were also daughters of Lavan, as were Rachel and Leah. As such, they were also part of Abraham’s family and carried the segulah (and genes) of the Nation of Israel. As opposed to them, Hagar was the daughter of Pharaoh, who is descended from Ham, the son of Noah – and not from Shem, who was the ancestor of both Abraham and Lavan. The holy Or Hachaim explains that Sarah never freed Hagar from her role as maidservant. Bilhah and Zilpah, on the other hand, were freed by Rachel and Leah, thus becoming full-fledged Jewesses. As a result of his lineage, Yishmael, the son of Hagar, was not good in his soul and his deeds – so much so that the Torah testifies “And he will be a wild man.” Conversely, the sons of Bilhah and Zilpah are counted among the Twelve Tribes of Israel.