Tachanun or Taḥanun (Hebrew: תחנון "Supplication"), also called nefillat apayim ("falling on the face") is part of Judaism's morning (Shacharit) and afternoon (Mincha) services, after the recitation of the Amidah, the central part of the daily Jewish prayer services. It is omitted on Shabbat, Jewish holidays and several other occasions (e.g., in the presence of a groom in the week after his marriage). Most traditions recite a longer prayer on Mondays and Thursdays.
On all days except Monday and Thursday (days when the Torah is read in the synagogue), Tachanun consists of three (in some communities two) short paragraphs. In most Ashkenazic synagogues, Tachanun begins with introductory verses from II Samuel (24:14), and then continues with Psalm 6:2-11, which King David composed - according to traditional sources - while sick and in pain. In the presence of a Torah scroll, this first paragraph is recited with the head leaning on the back of the left hand or sleeve (right hand when wearing tefillin on the left) as per Shulchan Aruch, Orach Chayim 131:1-2). The second paragraph, "שומר ישראל" ("Guardian of Israel") is recited seated, but erect (some communities only recite it on fast days). After this point, and following the words "va'anachnu lo neida", it is customary in many communities to rise, and the remainder of the final paragraph is recited while standing. Tachanun is invariably followed by "half kaddish" in the morning and by "full kaddish" in the afternoon.
On Monday and Thursday, a longer prayer commencing with Psalms 78:38 recited before (or after, depending on custom) the short Tachanun. It is recited standing. The length of this prayer varies according to community. Ashkenazic communities have the longest text of it; Sephardic (and Hasidic and Yemenite, in imitation of Sephardic) communities have a somewhat shorter, but similar, text; and Italian communities have the shortest text of all. The Italian text begins not with Psalms 78:38, but with Daniel 9:15.
The Talmud (Bava Kamma) marks Monday and Thursday as "eth ratzon", a time of Divine goodwill, on which a supplication is more likely to be received.
According to the Sephardic rite, Tachanun begins with viduy (confessional prayer). In this prayer several sins are mentioned and the heart is symbolically struck with the right fist during mentioned of each sin. This is followed by the mention of G-d's thirteen attributes of mercy. By and large, Sephardim do not have the custom of resting their head on their hand, but due to Ashkenazic influence in Morocco, some Moroccan prayer books include this custom.
The source of the supplicatory prayer (Taḥanun) is in Daniel (9:3) and I Kings (8:54), where the verses indicate that prayer should always be followed by supplication. Based on this, Talmudic sages developed the habit of adding a personal appeal to God following the set prayers (some examples are listed in the Babylonian Talmud, Berachot 16b). In the fourteenth century, these spontaneous supplications were standardized and turned into the prayer of Tachanun.
The custom of bending over and resting the face on the left hand is suggested by the first line of the text which includes the words "nip'lah na b'yad Adonai" ("let us fall into the hand of God"). It is also reminiscent of the Daily Sacrifice brought in the Temple, which was laid on its left side to be slaughtered. A person's arm should be covered with a sleeve, tallit, or other covering. This posture, developed in the post-Talmudic period, is symbolic of the original practice, in which people knelt down until their faces touched the ground to show humility and submission to God. The pose was also used by Moses and Joshua, who fell on their faces before God after the sin of the Golden Calf. Because of this practice, Tahanun is also known as nefilat apayim ("falling on the face"). Because Joshua fell on his face before the Ark, Ashkenazi custom is that one puts one's head down only when praying in front of an Ark containing a Torah scroll. Otherwise, it is proper to sit with the head up.
The longer version recited on Mondays and Thursdays is traced by classical sources (see e.g., S. Baer, Siddur Avodath Yisrael) to three sages who had escaped the destruction of the Jewish community in the Holy Land by the Romans. While on a ship on the way to Europe, they were caught in a storm, and all three recited a personal prayer, after which the storm subsided. These sages went on to establish communities in Europe. Abudirham states that the words "rachum ve-chanun" ("merciful and gracious") mark the beginning of the next segment.
Days on which Tachanun is omitted 
Tachanun is omitted from the prayers on Shabbat, all the major holidays and festivals (including Chol HaMoed, the intermediate days of Pesach and Sukkot), Rosh Chodesh (new moon), Hanukkah and Purim, as these days are of a festive nature and reciting Tachanun, which is mildly mournful, would not be appropriate.
The following is a list of all the other days, "minor holidays", when tachanun is excluded from the prayers. It is typically also omitted from the Mincha prayers the preceding afternoon, unless otherwise noted:
|9||Tishrei||The day before Yom Kippur (but not the mincha of the day beforehand).|
|11–14||Tishrei||The days between Yom Kippur and Sukkot.|
|24–29||Tishrei||From after Simchat Torah until the conclusion of the month (not a universal custom).|
|2||Shevat||(The day when a fire almost burned down the Ghetto of Rome, but the community was miraculously saved. Not a universal custom.)|
|15||Shevat||Tu Bishvat, New Year of the Trees.|
|14–15||Adar I||Purim Katan and Shushan Purim Katan|
|14||Iyar||According to some customs, Pesach Sheni (but not the mincha of the day beforehand; not a universal custom).|
|1–5||Sivan||The beginning of the month until Shavuot.|
|8–12||Sivan||(the Isru chag and compensentory week to bring an offering to the Temple in Jerusalem after Shavuot; not a universal custom)|
|29||Elul||The day before Rosh Hashanah (but not the mincha of the day beforehand, nor in the Selichos in the early morning).|
It is also not recited in the house of a mourner (see bereavement in Judaism), (reasons vary: either so as not to add to the mourner's grief by highlighting God's judgment, or because a mourner's house is a house of judgment, and a house of judgment is not a suitable place for requesting mercy) nor is it said in the presence of a groom in the sheva yemei hamishte (the seven celebratory days subsequent to his marriage, see marriage in Judaism). Additionally, Tachanun is omitted in a synagogue when a circumcision is taking place in the synagogue at that time, and when either the father of the baby, the sandek (the one who holds the baby during the circumcision), or the mohel (the one who performs the circumcision) is present. In many congregations, Tachanun is omitted if a simchat bat (naming ceremony for a baby girl) is taking place that day and one or both of the parents are present.
In Hasidic congregations, Tachanun is omitted on the anniversary of the death of various Rebbes (except Lubavitch makes a point of saying), since that is considered a day for religious renewal and celebration. There is a Hasidic custom of omitting Tachanun the entire week of Purim (11-17 Adar) and the entire week of Lag BaOmer (14-20 Iyar). Some communities omit Tachanun on 7 Adar because it is the anniversary of the death of Moses. Additionally some Hasidic congregations omit Tachanun on Friday mornings (getting ready for Shabbos), and some even on Sunday mornings (revival from Shabbos).
In many congregations, it is customary to omit Tachanun on holidays established by the State of Israel: Yom Hazikaron (Day of Remembrance of Israel's war dead), 4 Iyar; Yom Haatzmaut (Independence Day), 5 Iyar; and Yom Yerushalayim (the anniversary of the reunification of Jerusalem in 1967), 28 Iyar.
- http://www.thejewishpress.com/printArticle.cfm?contentid=29375 says that where the ark, containing a valid (non-Pasul) Sefer Torah can be seen from where one is sitting, then head down, if not, not. The article also has 3 other head-down situations: (a) some, in Jerusalem; (b) Sefer Torah without an ark; (c) at home, if one "knows at exactly what time the congregation recites Tachanun<italics> in the synagogue.
- Jewish Encyclopedia
- Jewish Virtual Library
- Naphillath Panim A historical perspective on Tachanun from a Yemenite and Maimonidean perspective.
- The Prayer Of Our Fathers Has translation of and guidance on how to pray the Amidah and Tachanun according to the Mishneh Torah
- Tahanun in Jewish Encyclopedia
- Forms of Adoration in Jewish Encyclopedia
- Rav Kook on Psalm 6, the Tachanun psalm for Ashkenazim