Bais HaVaad on the Parsha, Parshas Bo

Moonrise 

Excerpted and adapted from a shiur by Dayan Yehoshua Grunwald

January 6, 2022

This month shall be for you the beginning of the months, it is the first for you of the months of the year.

Shmos 12:1

The mitzvah of kiddush hachodesh (sanctifying the month) does not apply today, but we do have the mitzvah of kiddush levanah (sanctifying the moon). One interesting question that occasionally arises is whether one may recite kiddush levanah on Friday night.

The Maharil writes that if Shavuos falls on motza’ei Shabbos, one should not recite kiddush levanah, because just as the restriction of techum Shabbos prohibits a person from walking 2000 amos on the ground, so does it forbid him from elevating himself 2000 amos into the sky. (The same logic would forbid kiddush levanah on Shabbos.) The Bach explains that since saying kiddush levanah is like greeting the Shechinah (Sanhedrin 43a), it is considered as if one has ascended to the heavens and traversed the techum. Although some Rishonim, such as the Maharash and Rashba, question this ruling, the Rama (O.C. 426) accepts it as authoritative.

A number of Acharonim also question the Maharil and Rama on the grounds that a reshus hayachid (private domain) halachically extends up to the sky, so one who recites kiddush levanah in his yard should not violate the techum. Perhaps for this and other reasons, the Mishnah Brurah mentions only that there are kabbalah-based reasons for the ruling. In the Sha’ar Hatziyun, though, he offers an additional halachic reason: Since one should rejoice during kiddush levanah, there is a concern that he will dance on Shabbos, which is generally forbidden, even for a mitzvah (see O.C. 339 and Mishnah Brurah).

If Friday night is the deadline for kiddush levanah, the Mishnah Brurah says one may rely upon the lenient view.