וַיֶּעְתַּ֨ר יִצְחָ֤ק לַֽיהוָה֙ לְנֹ֣כַח אִשְׁתּ֔וֹ כִּ֥י עֲקָרָ֖ה הִ֑וא וַיֵּעָ֤תֶר לוֹ֙ יְהוָ֔ה וַתַּ֖הַר רִבְקָ֥ה אִשְׁתּֽוֹ׃
At taimtim at paulit-ulit na nanalangin si Isaac sa Walang-Hanggan alang-alang sa kanyang asawa, sapagkat siya ay baog; at dininig siya ng Walang-Hanggan, at naglihi si Rebeca na kanyang asawa.
Akeidat Yitzchak
When Rav Ashi, in Shabbat 156, advises the person born under the zodiac sign of Mars (symbolising bloodshed) to engage in vocations involving blood, such as becoming a ritual slaughterer or a mohel, someone who circumcises babies, this is meant to help such a person counteract his natural tendencies, sublimate them, channeling them into constructive activities. If Rav Ashi had been of the opinion that such a person's actions were predetermined, his advice would be totally gratuitous. Claiming that mazzal influences our lives, and claiming that mazzal governs our lives are two totally different propositions. Why would the Torah make rainfall dependent on our conduct (Leviticus 26,1-5) if our behavior were not free? The idea of receiving a reward for decisions made under duress would be difficult to swallow. Rabbah and Rav Chisdah, though sharing character traits and accomplishments, were born under different mazzalot. Each achieved what it was possible for him to achieve considering his respective mazzal. Perhaps Rav Chisdah having been born under the influence of a favourable mazzal, needed ninety-two years to achieve on this earth what Rabbah who had been born under an unfavourable mazzal had been able to achieve in forty years, seeing that he had to overcome so many obstacles? Consider the following parable. A king had two ministers. They both enjoyed equal status at Court. One was appointed commander of the king's land based forces, the other was made commander-in-chief of his navy. The commander of the navy obviously had the more challenging task. His task necessitated that he be away from home and family a great deal of the time, would be deprived of the comforts of home. He would also be deprived of the counsel and proximity of the king. The situation of Rav Chisdah and Rabbah may be viewed in a similar light. The Rabbis said in Taanit 2 that G-d reserved three keys for Himself which He did not entrust to messengers (nature). They are: 1) the key to life; 2) children, i.e. the key to being able to have them. 3) rainfall, i.e. the key to livelihood. The Talmud supplies scriptural proof for the fact that G-d retained these keys personally. In view of this, how is it possible to argue that three keys are not subject to one's merit, i.e. that one's behavior does not influence one's access to what these keys stood for? Why would G-d keep these three keys to Himself, except to use them in accordance with people's individual merits? Surely G-d did not keep them to Himself in order to use them capriciously! The answer is that although to begin with, these keys and their availability are subject to mazzal, man's merit does affect their availability. Abraham, according to his mazzal, would not have had children. Due to his merit however, G-d intervened and superimposed His will on that of natural law (compare Shabbat 156). Isaac found himself in a similar situation. Vaye-atar lo, G-d allowed Himself to be entreated by him (Genesis 25,21). G-d allowed Isaac's prayer to activate the key to "children." Compare also Taanit 25, the story involving Rabbi Eliezer ben Pedot. Because we have clear proof concerning these three matters from the lives of our historical giants, these instances were singled out for mention. When Rabbi Akiva, in Yevamot 50, says that those who deserve it have their lifespan completed rather than increased, this is based on his conviction that G-d has decreed the maximum good for each person at the beginning of such person's life. However, this maximum good is subject to review, i.e. reduction, if man does not live up to his respective potential.
Derashot HaRan
It is first stated that their mother did not conceive them within the conventional framework of nature (for she was barren), but as a result of Isaac's entreaties of the Blessed One on her behalf. These were accepted and she was healed. This may, at first glance, evoke doubt and wonder. For Rivkah did not fall to Isaac's lot adventitiously, but she was the woman designated for him by the L-rd (as seen in the episode of Eliezer). How, then, could He have chosen a barren woman as the lot of His "bound one"? This cannot be resolved except through the dictum of our sages of blessed memory (Yevamoth 64a): "The Blessed One desires the prayers of the righteous." For in this way He draws them close to Him, the soul uniting itself with its Creator in an abundance of prayer which cannot fail of acceptance.
Derashot HaRan
As far as its being written (Genesis 23:21): "And Isaac prayed next to his wife," our sages (Yevamoth 64a) expounded this as implying that Rivkah prayed together with Isaac, but that (Genesis, Ibid): "the L-rd was entreated of him," and not of her. But, according to this interpretation, it should have been written "And Isaac and Rivkah prayed." It may be, however, that the interpretation is derived from her prayer not being specifically mentioned but her praying being implied in the expression "next to his wife," this being consistent with homiletic interpretation.