Who did Isaac and Ishmael each marry, and how did their lines diverge?
Isaac married a wife from Syria among his relatives, continuing the spiritual line of promise. Ishmael married an Egyptian, and their genealogies were totally divergent. Though they reunited for their parents' funeral, spiritually there was no union between them; the bondwoman's son was not heir with Isaac.
Les teaches that Isaac and Ishmael came back together for the funeral of their parents, but spiritually there was no union between them. Isaac continued in the spiritual line and got a wife from up in Syria where the relatives were. Ishmael, on the other hand, married an Egyptian, producing a total divergence in the genealogies of these two young men. Les also emphasizes that the command to cast out the bondwoman and her son was not merely a mother's thought but the Word of God, so the son of the bondwoman would not be heir with Isaac.
But thou shalt go unto my country, and to my kindred, and take a wife unto my son Isaac.
And he dwelt in the wilderness of Paran: and his mother took him a wife out of the land of Egypt.
More Questions
Why did Ishmael marry an Egyptian?
Ishmael did not have the unction to be obedient to the will of God, so he married an Egyptian, contrary to God's instruction for Abraham's offspring not to marry Canaanites.