what is interesting is God used(s) Ishmael to lead His people into captivity when they,as a nation, turn their back on God. I feel its not so much as that God would reject them outright, but became a part of His redemptive plan for all, for out of the evil God will bring good from it. To suggest that they are rejected could imply they are not part of His redemptive plan, even though he was born to Hagar Gods promise to Abraham could not be taken back, His word does not return void with exceptions when He speaks, for Ishmael still enjoyed Gods providence in becoming a nation and being blessed in the land regardless that he wasn't born to Sarah. I never said it didnt I said he would be a nation. When you look at God's dealings with Israel, you are forgetting one big thing, and that is the covenant model.. all throughout scripture this is important, for when the Israelite's are punished by God for not staying within the covenant .. what do they say time after time after time... God is steadfast. He alone is Faithful. If you cannot see the covenant framework then you are missing what is going on! you have basically said what I said, gut missed the link what was so important in Scripture 'The covenant'.
another point, we all enjoy God's providence, for it rains on the just and unjust alike. However, those who do not enjoy Christ are condemned (Christs own words not mine).
as for Esau, he sold His inheritance for a morsel of bread, his selfishness to feed his own belly was more important than honoring his father, as is for us if we do the same, "MacDonald's Christianity" eat in or takeaway - now,and hows Jacobs form, he cheated Esau out of it to boot and still got the blessing from his father (Jacob=schemer) , makes one wonder yet know His ways are truly not ours, however being God, nothing is impossible