| Talmud: | Sanhedrin 41b–42a |
| Talmudy: | Berakhot 9:2 |
| Rambam: | Laws of Blessings 10:16–17 |
| Sa: | Orach Chaim 426 |
Kiddush Levanah is a Jewish ritual to bless God upon the appearance of the new moon.
The source of the Kiddush Levana is in the Babylonian Talmud:
Rabbi Yochanan taught that one who blesses the new moon, in its proper time, is regarded like one who greets the Shechinah (Divine Presence).[1]
The prayer, by its nature, is typically said outside at nighttime.[2] Many synagogues post the text of the prayer in large type on an outside wall, for greater visibility.[3] As such, the term "kiddush levana letters" has developed to refer to any text written in unusually large letters.[4]
The kiddush levana ceremony is performed on the first sighting of the new moon - performance at this time is deemed Hebrew: בזמנה - in its proper time, with some opining that only then is the blessing said while standing.[5] Rabbi Hayyim Vital[6] and the Rambam[7] adopted the view of the ceremony being done on the first night of the new moon. However, the normative custom is to wait three[8] or seven[9] complete days after the occurrence of the molad, or appearance of the new moon.
The latest time for Kiddush Levanah is when the moon is "filled in", and the amoraim debate if this means half full (until the seventh of the month) or completely full (mid-month).[10] The halacha follows the second opinion (mid-month).[11] The Shulchan Aruch[12] rules that it can be reciting through the night of the fifteenth of the month. Nevertheless, Rabbi Moses Isserles and other rules that it can be recited only until half way through the month literally, meaning fourteen days, eighteen hours and twenty-two minutes.[13] [14] There is another opinion that it can still be recited on the sixteenth of the month, as the waning of the moon is not yet recognizable;[15] however, if there is a lunar eclipse (which always occurs around the time of the full moon in the exact middle of the month), even this opinion would agree that it should not be recited after the eclipse since it is recognizable that it is after half of the month.[16] Another opinion allows it to be recited fifteen days from the Molad, irrespective on when Rosh Chodesh fell.[17]
In the month of Tishrei, most communities delay its recitation until after the conclusion of Yom Kippur;[18] others have a custom to say it specifically before Yom Kippur.[19] In the month of Av, it is traditionally postponed until after the fast of Tisha B'Av, as the beginning of the month is a time of mourning and the prayer should be said in a spirit of joy. While some avoid reciting it on the night after Tisha Bav since there is still an element of mourning, or at least until they have had a chance to eat something and put on leather shoes,[20] others allow it to be recited immediately after Tisha Bav.[21] If a Festival falls on Sunday, Kiddush Levanah is delayed until after that day.[22] Kiddush Levanah is generally not recited on the night of a Sabbath or Festival, although if it is the last opportunity to do so one may recite it even on the Sabbath or a Festival.[23] However, in such a situation only the blessing should be recited and the additional passages should be omitted.[24]
Kiddush levana is preferably recited at the conclusion of Shabbat.[25] However, if waiting until the conclusion of the Sabbath will make it impossible to recite it before the tenth of the month, it should be recited on weekday out of fear of missing out completely.[26] Some opinions recommend recited it right away and never waiting unil the concusion of the Sabbath.[27]
The moon must be visible and not totally covered by clouds,[28] and the ceremony is preferably performed outside, as opposed to looking at the moon from a window.[29] While it is customary to say the prayer with the large crowd after the Saturday evening services, or at least with a minyan, it can be also said without a minyan and in the middle of the week.[30] In places where cloudy or rainy weather is very common, many people will recite the blessing as soon as they see the Moon for the first time after the requisite number of days.[31]
It is customary to say additional passages in addition to the blessing; some of these are mentioned in Masekhet Soferim,[32], some are mention in the writing of Rabbi Hayim Vital[33] and others appear in Siddurim but do not have a clear source.
Normally, women are exempt from time-bound positive commandments.[34]
The Talmud says that the practice of women is to recite this blessing.[35] Rabbi Shlomo Kluger explains that it is not a time-bound commandment because it is dependent on the new moon and not directly on time.[36] However, the Magen Avraham rules that it is a time-bound commandment from which women are exempt, and he further says that the practice of women is to specifically not recite this blessing due to Kabbalistic reasons (as opposed to other time-bound commandments which women may choose to preform).[37]