It is customary to hold celebrations on Ḥol Ha-mo’ed, in commemoration of the Simḥat Beit Ha-sho’eva held in the Temple. Every celebration held during the festival is a mitzva, as we read, “You shall rejoice in your festival” (Devarim 16:14). These commemorative celebrations, also called “Simḥat Beit Ha-sho’eva,” fulfill an additional mitzva by invoking the Temple celebrations and thus hasten the Temple’s rebuilding (Sukka 41a).
This custom has become stronger in recent centuries, as Jews from all over the world began to gather in Eretz Yisrael, and the light of salvation began to glimmer. Originally, these celebrations were held only in Eretz Yisrael, but they spread to the Diaspora as well. As R. Ḥayim ibn Attar (the “Or Ha-Ḥayim”) wrote in a letter from Jerusalem in 5503 (1742): “On Ḥol Ha-mo’ed we had a Simḥat Beit Ha-sho’eva. I was the one who lit [the torches] one night, and we held a great celebration.” Elsewhere it is recounted that people would dance in circles, holding torches. Similarly, Ḥasidim who immigrated to Israel from Europe reported that a Simḥat Beit Ha-sho’eva with drums, dancing, and torches was held in Tzefat.
Yehosef Schwartz (d. 5625/1864) wrote a letter to his brother about the special celebrations that took place in Jerusalem. He described how in the Kahal Tziyon Synagogue they set up a special device that shot water upward during the celebration. R. Yehuda Leibish Orenstein (head of the Ḥasidei Yerushalayim rabbinical court) wrote (in 5633/1872) that the Sadigora Ḥasidim who immigrated to Jerusalem hired non-Jewish musicians to play every night of Ḥol Ha-mo’ed at their Simḥat Beit Ha-sho’eva (Responsa Moharil, p. 8). However, the general Ashkenazic custom was not to light torches (Ir Ha-kodesh Ve-hamikdash 3:25:8-9).
Ḥayim Abulafia instituted a Simḥat Beit Ha-sho’eva in the synagogue in Izmir, Turkey, to commemorate the Temple, in which they lit many candles in the synagogue and played hymns for about two hours, with dancing by elders and notables (Ḥayim Va-ḥesed 497:11). Similarly, the Rabbi of Tripoli in 5570/1810, R. Avraham Ḥayim Adadi, wrote that they customarily celebrated on Ḥol Ha-mo’ed nights, following the practice instituted by an emissary from Jerusalem. They sang and danced for two or three hours, with the sexton handing out candles to the dancers. Each dancer began by bowing in front of the holy ark (Vayikra Avraham, Kuntres Makom She-nahagu, p. 123). Some even permitted a mourner to play music at the Simḥat Beit Ha-sho’eva, since its joy is that of a mitzva and it commemorates the Temple (Zera Emet 2:157). Some sang selected liturgical poems of the Days of Awe during the Simḥat Beit Ha-sho’eva (Yesod Ve-shoresh Ha-avoda 11:14).
Even though there is no obligation to hold a Simḥat Beit Ha-sho’eva, having one is a mitzva. It is especially important to encourage those who are not studying Torah to participate in the celebration, rather than to waste their time (R. Yaakov Ettlinger, Bikurei Yaakov 661:3).
At the beginning of the celebration, some have a custom to recite the fifteen “Songs of Ascent” (“Shir Ha-ma’alot”; Tehilim 120-134), which have special power to increase water and blessing. The custom is based upon the story that when King David opened the Shitin, the waters of the deep threatened to rise and flood the earth. David wrote the Tetragrammaton on a potsherd and placed it upon the water. The water sank 16,000 amot, and the world became very dry. Then King David recited the fifteen “Shir Ha-ma’alot” psalms, and with each psalm, the water rose 1,000 amot, and the world was once again hydrated (Sukka 53a-b).