Genesis 27-29

In 28:13-15 God repeated the promise of blessing to the third generation of the men of faith. It was an important message so God not only repeated it to each generation he continued that practice through the generations. Abraham may had first heard that promise at least a century earlier but neither the promise or the God who spoke it had changed. It is the same way with God's message of the Gospel. He had made a promise of enduring grace that has not changed over the generations. And in reality it is the fulfillment of the promise God had made to Abraham those thousands of generations earlier.
Stuart