What we are seeing at the beginning of chapter 25, is the effect of Abraham’s healing by God at the time that Isaac was conceived, that the healing was not just a one shot affair, that Abraham married after Sarah died and continued to produce children well after he was 137 years of age. Now how long after that I do not know. But it does show Abraham’s posterity beginning to multiply toward the end of his life.
What we see here then is a complete rejuvenation of Abraham’s powers. It is quickly stated in verses 5-6 that the bulk of the inheritance went to Isaac, and he died at a good old age, even as God had prophesied back there in Genesis 15:15, where He prophesied to Abraham that he would go to his grave in peace and die in a good old age. One hundred and seventy-five years, and one hundred of them living by faith.
