Gen 22:2 “Take your son, your only son—yes, Isaac, whom you love so much—and go to the land of Moriah. Go and sacrifice him as a burnt offering on one of the mountains, which I will show you.”
Sometimes God refuses to acknowlege a reality based on the flesh or human effort, versus a reality based on faith. Isaac was born out of faith, whereas Ishmael out of human effort or the works of the flesh to bondage. God still loved Ishmael and provided for him, but the promise and inheritance went to Isaac. Until this day, Ishmael is still trying to grab this inheritance from Isaac by their determination to destroy the Jewish nation and take away Jerusalem. Ironically, it is said, that Abraham took Isaac to Jerusalem to be sacrificed. It is this very place appointed that Israel has its everlasting inheritance.