Answer: As we know, there are three different lineages among the Jewish nation: Kohanim, Levi’im, and Yisraelim. The sanctity of the Levi is greater than that of the Yisrael and the Kohen’s sanctity is the highest of them all. The question therefore is whether or not a regular, non-Kohen Jew, may marry a Kohen’s daughter? The same question applies the other way around: May a Kohen’s daughter marry a regular Jew or must she specifically seek to marry a Kohen like her?
The root of this question lays in the Gemara (Pesachim 49a) which states: “The Baraita states: Rabbi Shimon says: A Torah scholar may not partake of any meal which is not in celebration of Mitzvah. What is an example of a meal which is not in celebration of a Mitzvah? Rabbi Yochanan said such as the wedding celebration of a Kohen’s daughter marrying a Yisrael or a Torah scholar’s daughter marrying an ignoramus.” Rashi (ibid.) explains, “A Kohen’s daughter must marry another Kohen and not blemish her family by marrying a Yisrael.” The Gemara continues: “Indeed, Rabbi Yochanan said: The union of a Kohen’s daughter and a Yisrael will not be successful.” The Gemara then questions this: “Did Rabbi Yochanan not say that one who wishes to become wealthy should cleave to the offspring of Aharon, for Torah and Kehuna (priesthood) make them wealthy?” The Gemara replies: “There is a distinction between a Torah scholar and an ignoramus.” This means that if the man marrying the Kohen’s daughter is an ignoramus (one devoid of Torah and fear of Heaven) the union will be unsuccessful; however, if the man is a Torah scholar, it is auspicious for him to marry the Kohen’s daughter. Rashi comments likewise and explains that an ignoramus marrying a Kohen’s daughter is an insult to the honor of Aharon Ha’Kohen in that such an individual cleaves to his offspring and the individual is therefore punished for this.”
Based on this, a Torah scholar may marry a Kohen’s daughter but an ignoramus may not and if he does, the marriage will be unsuccessful. The Rambam (Chapter 21 of Hilchot Issurei Bi’ah, Halacha 31) rules likewise. The Tur and Maran Ha’Shulchan Aruch (Even Ha’Ezer, Chapter 2, Section 8) rule as follows: “An ignoramus should not marry a Kohen’s daughter and if he does, the marriage will be unsuccessful, meaning that either he or she will die prematurely or a calamity will befall them. However, a Torah scholar marrying a Kohen’s daughter is a good and worthy thing, for this causes Torah and Kehuna to be joined in one place.”
The original words of the Gemara which we have quoted deal with the definition of a meal in celebration of a Mitzvah and writes that a wedding celebration of an ignoramus and a Kohen’s daughter is not a meal in celebration of a Mitzvah. The Responsa Chavot Yair (Chapter 70) writes that nowadays, even the wedding celebration of an ignoramus to a Kohen’s daughter is considered a festive meal of a Mitzvah, for nowadays, the status of “ignoramus” to which our Sages referred no longer applies. He proceeds to support this idea with proofs. Maran Rabbeinu Ovadia Yosef zt”l explains that even according to the Chavot Yair, not every individual is permitted to marry a Kohen’s daughter. The individual must, at the very least, be involved with Mitzvot and acts of kindness, for although he does not study Torah, such an individual is still valid to serve as a witness and is not considered an ignoramus. However, an individual who is not Mitzvah-observant whatsoever is invalid to serve as a witness and he certainly bears the status of an ignoramus for whom it is an insult to Aharon Ha’Kohen for him to marry into his offspring.
After discussing this matter at length, Maran zt”l separates this matter into three categories: If the individual is a Torah scholar, it is an honor for him to marry a Kohen’s daughter. Indeed, such a person will merit much wealth and honor, for he is causing Torah and Kehuna to come together.
If the individual is an ignoramus who possesses not Torah, Mitzvot, or acts of kindness, it is an insult to Aharon for such a person to marry into his offspring and one should certainly try as much as possible to prevent such a person from marrying a Kohen’s daughter, for this poses a danger to them both. This is what the Gemara means when it says “When one who marries off his daughter to an ignoramus, it is as though he has tied her up and placed her in front of a lion,” for it is almost certain that they will not observe the laws of family purity since one who is suspected of desecrating the Shabbat is suspected of transgressing all of the prohibitions of the Torah.
If the individual is a layman who has not studied Torah but is Mitzvah-observant, performs acts of kindness, and follows the correct path, he may marry a Kohen’s daughter, for there is no honor or insult in this union.
Summary: A Yisrael should not marry a Kohen’s daughter unless the groom is G-d-fearing and has set times for Torah study. This is especially true if the young man studies in a Yeshiva although he may not yet be considered a Torah scholar. However, if the groom is not Mitzvah-observant and does not follow the correct path of the Torah, such an individual should not marry a Kohen’s daughter. Likewise, the woman should distance herself from such a match that is not befitting of her lineage.