Participation in a Neighbor's Wedding During the Year of Mourning

Can a mourner within the year of mourning for his mother attend a neighbor's wedding by serving as a waiter there?

After thirty days, one can be present at the chuppah if it is outside the hall and there are no musical instruments. One should not enter the hall, but if the neighbors need him at the wedding, leniency can be applied by serving the guests from the beginning of the meal until its end. This way, he can be in the hall during the meal, even eat, and leave for home during the dancing.

The Rema writes in Siman 391: "Some permit a mourner to eat at a wedding feast or a circumcision with the attendants, provided it is not in a place of joy, such as another house (Kol Bo and Beit Yosef in the name of Smak), and some prohibit it (Hagahot Ashri), and this is the custom, except that the mourner may serve there, if he wishes, and eat at home from what is sent to him from the feast." Thus, the opinion of the Rema is that even if he serves at the feast, he eats at home, but the Reak"a wrote: "In Belz it is written that in Poland the custom is that the groomsmen also go to eat, but initially serve a little." The custom of Poland allows a little service at the beginning only for relatives and groomsmen, but regarding neighbors, the custom is to be strict. However, he can be at the feast as a real servant from beginning to end, as the Rema wrote. What I wrote that as a servant he can eat is because they rely on the opinion of the Maharshal, who wrote in Shut Maharshal, part Yoreh Deah, Siman 202, regarding the participation of brothers within the year: "We learn from this case that brothers are allowed to enter their brother's chuppah within the year, as there are no closer ones than them [and it would be distressing for the groom if they do not participate in his chuppah]. And this is all the more so, as the mitzvah of sukkah, which is from the Torah, is deferred so as not to distress the groom, mourning for twelve months, which is the lightest of the light, all the more so." And there it is explained that even according to the opinion of the Raavad, who is strict and holds that only at the wedding of an orphan and an orphan is it permitted, this refers to the wedding of a non-Jew who is not part of the chuppah, but brothers who are part of the chuppah, it is permitted. And there it is permitted even within thirty days, and so it is written in Shut Sheilat Yaavetz (part 2, Siman 179). If he is not so needed at the feast, he can participate in the chuppah outside the hall, as written in the Tur, Siman 391: "And Rabbi Yehuda Albarceloni wrote that there is a custom to enter within twelve months to the chuppah to hear the blessing or to visit, but not to eat, and there are those who are strict not to enter at all, and the Ramban wrote that it is forbidden to enter there at all, whether during eating or when they are engaged in the entertainment of the groom and bride, and so wrote the Rosh, and so it is customary in Ashkenaz that all twelve months stand outside the house to hear the blessings and do not enter the house at all." And so the Shulchan Aruch ruled to prohibit, and the Rema wrote: "And all this in the house where they make the wedding and eat and drink and rejoice there, but at the chuppah that they make in the synagogue, where they bless the blessing of betrothal and marriage, and there is no joy at all, it is permitted immediately after seven days (Hagahot Maimoni). And there are those who prohibit until thirty (there in the name of Raavia), and so it seems to me." Therefore, it is permitted at the chuppah outside the hall, but not inside the hall. And during the dancing, he goes home, as written in Shaarei Teshuva, Siman 551, SK"A.