Gênesis 25
Bede
Gênesis 25:7
Isaac, the son of the promise, was born in Abraham's hundredth [year], because the blessing of the inheritance that is promised to all the families of the earth through his seed will doubtless be conferred in the heavenly homeland that is to come. [Abraham] sojourned a hundred years in the land of promise, because all of us who are made children of Abraham through faith ought to live as sojourners in the present church in hope of a heavenly inheritance. In this manner, "Isaac sowed in Gerar (which is interpreted as "residence [as an alien]"), and "in that same year he acquired a hundredfold," because as soon as we go forth from the body into the heavenly life, we receive back whatever good works we have done while sojourning in this life as children of the promise. — On the Tabernacle 2.13.85
Gênesis 25:21
Thus Isaac, the son of the promise, who as a figure of our Redeemer became obedient to his father even unto death, was born of parents who were old. He had a mother who had long been barren. Thus Jacob, the patriarch Joseph, Samson, [who was] the bravest of the chieftains, and Samuel, [who was] the most distinguished of the prophets, [all] had as their progenitors [mothers who were] for a long time barren in body but always fruitful in virtues. In this way their dignity would be known from the miraculous nativity of those who were born, and it might be proven that they would be famous in their lives, since at the very outset of their lives they transcended the norms of the human condition. — Homilies on the Gospels 2.19