How did Abraham receive God’s blessings? He received them just as God says in the Scriptures: “because you have obeyed my voice.”
For God, Abraham’s obedience had already passed the test, what he did was sufficient, and God had already seen the outcome of what He intended to do.
God caused Isaac to be born at the time He had set. Do the facts prove that the behavior and conduct of man hindered the work of God? They did not hinder the work of God!