“Sarah’s Demand: Protecting the Promise” When Isaac, the promised child, was born to Abraham and Sarah in their old age, Sarah saw Ishmael, the son of Hagar the Egyptian slave, mocking Isaac (Genesis 21:9). Fearing that Ishmael would share in Isaac’s inheritance or influence him wrongly, Sarah said to Abraham: “Cast out this slave woman and her son, for the son of this slave woman shall not be heir with my son Isaac.” — Genesis 21:10 Sarah’s reason was rooted in protection of the covenant promis