The joy of redemption
מלא שבע זאת ונתנה לך גם-את-זאת גו’
Complete this week, and she will be given to you [in marriage] as well…
The Mishnah teaches us that it is forbidden to get married on Yom Tov, as well as the intermediary days of Yom Tov. The reason given is that it is a simcha, a joyous event. Why is that a reason to forbid it on Yom Tov?
The gemarra gives various explanations. One explanation is ein mearvin simcha besimcha, it is forbidden to mix two joyous occasions. Sounds like any joyous occasion shouldn’t be mixed with another. What’s the source for such a concept? The gemarra derives it from King Shlomo, who completed the building of the Temple seven days before the festival of Sukkos. He made a nationwide seven-day festival in honor of the event, and then the nation celebrated the seven days of Sukkos. The verse stresses that he made a seven-day festival, and only then there was the seven days of Sukkos. This seemingly superfluous information teaches us that it would have been forbidden to combine the two events.
Another source is brought from this week’s parsha. After Yaakov was tricked into marrying Leah, his father-in-law Lavan told him to wait after the week of celebrations before marrying Rochel. Only then would he be allowed to marry the women whom he originally intended to marry. We see from this that it was understood not to mix two celebrations.
Does pidyon haben have the issue of ein mearvin simcha besimcha, at least when it comes to performing it on Yom Tov? Tosafos are unsure about the matter. What would be the simcha associated with a pidyon haben? One suggestion could be simply the simcha of fulfilling this mitzvah. It’s not as common a mitzvah as others. It’s only once in a father’s life. Their wife’s firstborn needs to be a son. Neither of them can be kohanim, leviim, or be children of kohanim or leviim. Perhaps the joy is fulfilling this rarer mitzvah. Indeed, this is the reason why there’s an accompanying blessing of shecheyanu, which is recited when performing mitzvos of simcha.
While this may be true, it would appear that some prohibit getting married on Yom Tov only if there’s the traditional festive meal. It would seem that the same should apply to a pidyon haben. While the mitzvah could have inherent joy, the mitzvah on its own wouldn’t be forbidden on Yom Tov. Only in conjunction with a festive meal would there be a question. Indeed, Tosafos only mention uncertainty with regards to the festive meal of a pidyon haben. It sounds like the pidyon haben alone would be fine . Now would be a good time to analyze the idea of a meal at a pidyon haben, how exactly to define it.
Certain mitzvos require a festive meal to accompany it, such as a wedding. The gemarra doesn’t list any specific requirement to have a meal at a pidyon haben. It is however something that has been the custom for almost two millennia. What’s the purpose of such a meal? I would have said it’s to accompany the celebration of such a joyous mitzvah. However, many authorities give a different explanation. They say it’s to publicize the pidyon haben, so everyone will know that this first-born boy was redeemed. Perhaps this was Tosafos’ dilemma. If the reason for the festive meal is simcha, then there could be an issue of ein mearvin simcha besimcha. If the reason for the meal is to publicize the pidyon haben, then there shouldn’t be any issue. Maybe Tosafos wasn’t sure how to define the purpose behind the meal.
In any event, the final halacha is that it is permissible to have a pidyon haben with its accompanying meal on the intermediary days of Yom Tov. The reason being that the biggest simcha comes from celebrating a marriage. Therefore, ein mearvin simcha besimcha only applies to celebrations of equal stature. This would then permit a pidyon haben on Yom Tov.
 Based on my own research
 Genesis 29:27
 Moed Katan 8b
 Moed Katan 9a; Yerushalmi Moed Katan 1:7
 I Kings 8:65
 Yerushalmi Moed Katan loc. cit., brought by Tosafos to Moed Katan 8b s.v. לפי שאין
 Ad. loc. s.v. מפני ביטול
 Tosafos to Sukkah 46a s.v. העושה; Sefer Rokeach § 371; Abudraham Sha’ar Shlishi. Abudraham says the simcha for this שהחיינו is that the child survived to thirty days, proving to not be a stillborn. Ba’al HaMeor to Pesachim 28a s.v. ובספירת say this is why we say שהחיינו but doesn’t mention the simcha aspect. Rokeach, Piskei Rosh Bechoros 8:8, and Tosafos HaRosh to Sukkah 46a just say this is why we say שהחיינו at a pidyon haben and not at a bris milah, as then the child still hadn’t survived thirty days
 Tosafos to Kesubos 47a s.v. דמסר לה say that while getting married has intrinsic simcha, it’s not enough to prohibit getting married on Yom Tov. Only with a festive meal is it forbidden. Chochmas Shlomo ad. loc. asks on this from Moed Kattan 18b which prohibits nisuin, marriage on Yom Tov, as well as a seudas eirusin, a betrothal meal. This would imply that the nisuin mentioned is without a meal, and nevertheless it is prohibited on Yom Tov. He answers that Tosafos understood that case to be a case of eirusin and nisuin combined, which even without a meal is prohibited. However, nisuin alone would be fine on Yom Tov. He admits that the poskim don’t make such a distinction between eirusin and nisuin versus nisuin alone, and both are forbidden. Cf. Maharsha, who rejects this solution, and suggests that Tosafos just mean that it’s biblically forbidden with a festive meal, and rabbinically forbidden without a meal. Therefore. it would seem ein mearvin simcha besimcha always applies, even without a meal. This explanation is brought by the Sha’ar HaTizyun to Shulchan Aruch Orach Chaim 546:1 § 1. The Magen Avraham ad. loc. § 1 asks similarly on Tosafos, and suggests that Tosafos were saying this only according to the opinion of Rav, who says the reason it’s forbidden to get married on Yom Tov is ושמחת בחגך, ולא באשתך. He suggests that this is only with a meal. He says however that we rule the reason is ein mearvin simcha besimcha, which applies even without a meal. See Aruch HaShulchan ad. loc. § 4, who gives another approach to Tosafos, and is perplexed why the above authorities struggled to resolve Tosafos, as he feels his is the simplest approach. What comes out is everyone assumes Tosafos’ differentiation between having a meal or not is not practically relevant. However, see next note
 Even though the above authorities reject the plain reading of the words of Tosafos, perhaps this differentiation is still true for mitzvos other than getting married. Maybe the joy of getting married is so great that it doesn’t require a festive meal to be prohibited on Yom Tov. However, mitzvos like pidyon haben and bris milah would only forbidden with a festive meal. Otherwise, I’m at a loss for why Tosafos only mention the festive meal of a pidyon haben and bris milah
 Tosafos say that a bris milah and its festive meal are fine to have on Yom Tov. One reason given is the gemarra says there’s צערא דינוקא, pain for the child (Kesubos 8a; see Be’er HaGoleh to Shulchan Aruch Yoreh Deah 265:7 § 15 who refutes those that think this is why there’s no שהחיינו at a bris milah). Although the gemarra does say bris milah is a mitzvah that is always done with joy (Shabbos 130a), apparently the pain of the child offsets any issues of ein meravin simcha besimcha. Besides, this joy might only apply to the mitzvah itself, but during the meal itself all that’s left is the pain of the child
 Rashi and Tosafos to Bava Kamma 80a s.v. (לבי) ישוע הבן explain the gemarra to be describing such a meal, attended by the third century ammoraim Rav, Shmuel, and Rav Asi. Sefer HaAruch § ישע concurs. The custom to have such a meal is codified by the Rema to Shulchan Aruch Yoreh Deah 304:10
 Hagahos Mordechai to Yevamos § 127. Teshuvos Maharam Shik Even HaEzer 89:2 explicitly suggests that perhaps the pidyon haben meal is not for simcha but rather for pirsumei milsah. See also Terumas HaDeshen § 269, brought by the Shach to Shulchan Aruch Yoreh Deah 305:11 § 12, and Sha’arei Teshuvah to Shulchan Aruch Orach Chaim § 568:2 § 5
 This is also the reasoning to have ten men present at the pidyon haben
 Shulchan Aruch Orach Chaim 546:4. It’s interesting that the Shulchan Aruch refers to the meal being permitted on Yom Tov. This could be related to what I noted in note 10. However, he’s just following what Tosafos discusses, as clear from the Beis Yosef ad. loc.
 Tosafos’s final answer. Be’ur HaGra ad. loc. and Mishnah Berurah ad. loc. § 11