This week’s parshah begins by telling us that Yitzchak was 40-years-old when he married Rivka. Rashi tells us that Rivka was born at the akeida, when Yitzchak was 37-years-old. Yitzchak then waited three years until Rivka was 3-years-old and then he married her.
The Maharal in Gur Aryeh asks based on the Gemara in Nidda 13b and in Keddushin 41a which states that a gadol should not marry a ketanah. Why then did Yitzchak marry Rivka when she was only 3? The Gemara Yoma 28b tells us that the Avos kept the Torah; even the rabbinic prohibitions. The Maharal suggests several answers. One is that the Gemara in Yevamos 64 says that Yitzchak was an akar (barren). The prohibition not to marry a ketanah does not apply to an akar.
It is unclear as to why one should not marry a ketanah. Rashi in Niddah explains that it is because a ketanah is not able to bear children until she becomes a gedolah. Therefore one who marries her will be nullifying the mitzvah of pru u’revu until that point. Based on this explanation we can understand why an akar would be permitted to marry a ketanah.
The Maharal suggests another answer. Since, as the pasuk says, the matter was orchestrated from Hashem, Yitzchak felt that Hashem allowed this. We find that in certain circumstances before the Torah was actually given, people were permitted to make calculations as to what would better serve Hashem, even if it were against a mitzvah or aveirah. However, after the Torah was given we are not allowed to make our own calculations as to what would serve Hashem better; rather we must follow the Torah regardless of any other calculations.
The Maharal suggests another answer as well. The halachah is that a father may marry his daughter who is a ketanah and the kedushin is binding m’d’Oraisa. However if the father is dead and her brother or mother marry her off the kedushin is only m’d’Rabanan and when she becomes a gedolah she may refuse the marriage (this is known as me’un). He says that it is only prohibited in a scenario where it is the girl’s father who marries her off, where the kedushin is binding m’d’Oraisa. However, in a scenario where the girl’s father is dead and her mother or brother marries her off, it is permitted to marry a ketanah, since when she becomes of age she can refuse the marriage.
The Maharal points out that Eliezer had intended to bring Rivka back even while her father Besuel was alive. Tosafos in Kesubos 7b says that Eliezer was a shliach to perform kedushin on Rivka. Nevertheless, since Besuel was a goy and Rivka was a convert, she was considered to be an orphan in halachah. Therefore even if Besuel was alive when Eliezer was mekadesh Rivka it would not be binding m’d’Oraisa, and when she would become a gedolah she would be able to refuse the marriage. Therefore it was permitted for Yitzchak to marry Rivka while she was a ketanah.
Some Achronim ask on the Maharal based on the following Gemara: The Gemara in Sota 10a explains that when Yehudah met Tamar at the crossroads he asked her several questions. First he asked her whether she was Jewish or not. She responded that she was indeed a convert (as were all “Jews” at that time). He then asked her if she was married, to which she responded in the negative. Yehudah then asked if perhaps her father accepted kedushin when she was a ketanah. She responded that she was an orphan. The Gemara continues to explain other questions that Yehudah asked Tamar, however it is evident from the Gemara that even after Yehudah learned that she was a convert, he continued to inquire whether her father accepted kedushin when she was a ketanah. This implies that the father of a girl who converts, even though her father did not convert, can still marry her off.