פּירוש אויף בראשית 25:24

“When her time to give birth was at hand, there were twins in her womb” [25:24]. The nine months of pregnancy ended and there were twins in her womb. Toldot Yizhak writes. Why did Isaac not pray immediately for Rebecca and waited for ten years? The explanation is that he prayed immediately. The Holy One said: it would be good if the evildoer should not be immediately born into this world. Rebecca said: if an evildoer is to be born, let him not be born immediately. That is why it is written, “When her time to give birth was at hand.” The nine months had been completed. That is, the Holy One caused the evildoer to tarry in his mother’s womb, that he should not leave early. However, Moses Our Teacher, the righteous one, left his mother’s womb when he was only six months and several days in his mother’s womb.¹⁷Toldot Yizhak, Genesis, 25:19–26.

That is why it is written, “there were twins” [25:24], without an aleph, because one was an evildoer and the other one was righteous. However, concerning Tamar, they were both righteous, Peretz and Zerach. Therefore, it is written concerning Tamar, twins, with an aleph.¹⁸Bahya, Genesis, 25:24.

Some ask why Rebecca did not ask Isaac, what is the meaning of the children struggling with each other, since Isaac was also a prophet? The explanation is that Rebecca did not want to say that she was having trouble with her pregnancy. Isaac would say that she had more anguish than other women because she had more sins than other women and Isaac would divorce her. Therefore, she did not want to tell him.

וימלאו ימיה AND WHEN HER DAYS TO BEAR WERE FULL — But in the case of Tamar it is written, (37:27) “And it came to pass at the time of her travail”, for her days were not fulfilled as she gave birth to them (her children) at the end of seven months.