When exactly was Yitzchak born?
Rashi #1: There are two opinions in the Midrash Rabah as to whether Yitzchak was born after nine months, or after seven. 1 (However, both opinions in Rosh Hashanah 10b agree that he was born on Pesach.)
Rashi #2: Based on the word "Oso," 2 the Tanchuma explains that he was born exactly one year later (on Pesach).
What does "la'Mo'ed" mean?
Rashi #1: It means after nine months (the appointed time that a woman gives birth). 1
Rashi #2: It means after seven months (the time to which the angels referred earlier in the Parshah).
Rashi #3: Exactly one year later, when the sun reached the same point on the wall as it had been when the angels came to see Avraham. 2
What is the meaning of 'li'Zekunav"?
Targum Onkelus and Targum Yonasan #1: It means literally 'in his old age.'
Targum Yonasan #2 and Rashi: It is the acronym of 'Ziv Ikunin' (his shape of face), because Yitzchak's face was strikingly similar to that of Avraham.
Why does it need to say that Sarah conceived? It suffices to say that she gave birth!
Da'as Zekenim: They are put together to teach that just like she became pregnant without pain, she gave birth without pain. 1
Sotah 12a expounds so about Yocheved. Righteous women are not subject to Chavah's curse.
QUESTIONS ON RASHI
Rashi writes: "'At the appointed time, that He had spoken it (Diber Oso)' - [Targum translates] 'd'Malil Yasei,' the time that he had spoken and set... [The angel] had etched a line on the wall; and when the sun would reach the mark next year...." Why does Rashi cite the Targum, add the word "set," and illustrate with this example?
Gur Aryeh: It is difficult to explain that the "appointed time" (Mo'ed) is the direct object of the verb "spoken," for speech does not affect time. 1 We also cannot translate, 'the appointed time that He had spoken with him (i.e. Avraham),' as Targum makes clear. 2 Rashi therefore explains that HaSh-m did not merely speak [though the angel], but rather He actively set a time that the baby would be born, giving a tangible mark.
