Why was Ishmael's marriage to an Egyptian contrary to God's will?
Ishmael's marriage to an Egyptian was contrary to God's will because he lacked the unction to obey God, and God had instructed Abraham's offspring not to marry the Canaanites. His union with an Egyptian reflected disobedience to God's desire for Abraham's line.
Les teaches that Ishmael, like Esau, serves as an example of the works of the old Adamic nature. Ishmael did not have the unction to be obedient to the will of God, so he went and married an Egyptian. This was contrary to what God wanted for the offspring of Abraham, because God had instructed them not to marry the Canaanite. Esau later did the same by marrying Canaanite women already steeped in immorality and wickedness. Paul uses these examples to show that sexual sin and disobedience are often listed first among human sins.