One of the greatest mitzvot, and one of the most enjoyable, is that of “Simchat Chatan v’Kallah,” bringing joy to a bride and groom. One way in which this is accomplished is through the institution of “Shabbat Kallah.”
In the traditional Ashkenazi community, the bride and groom do not see each other during the week before the wedding. The Shabbat before the wedding* is particularly exhilarating and, at the same time, anxiety filled. To calm the bride and make her joyous on Shabbat afternoon, her female family and friends host a small gathering for her -- usually at the time of Seuda Shlishit (the third Sabbath meal).
While the Shabbat Kallah is a fairly new tradition and there are no set customs or ceremonies, it could perhaps be seen as a religious “bachelorette” party. In addition to divrei Torah (words of Torah), the women share with the bride words of wisdom (about marriage) and their blessings for a beautiful wedding and a happy future.
Even though there are no sources for this particular tradition, a celebration for the bride on Shabbat seems appropriate, since Shabbat itself is often referred to as a “kallah.” According to the Midrash (Jewish legend) cited in Bereishit Rabbah (11:8), the Sabbath declared: “Master of the Universe, every day of the week has a mate except for me!” The Almighty answered: “The People of Israel will be your mate.” Thus, Shabbat and the Jewish people were brought together in a holy union, just as a bride and groom form a holy union on the day of their wedding.
*On Shabbat morning, the groom celebrates his “aufruf,” when he is honored with an aliyah (being called up) to the Torah.