Tachanun or Taḥanun ( "Supplication"), also called nefilat 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 also recited at the end of the Selichot service. 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.
Format
There is a short format of Tachanun and there is a long format. The long format is reserved for Monday and Thursday mornings, days when the Torah is read in the synagogue. The short format, recited on other weekdays mornings and on weekday afternoons, consists of three (in some communities two) short paragraphs.
According to the Nusach Sefard and most Sephardic rites, Tachanun begins with vidduy (confessional prayer) and the Thirteen Attributes; in Spanish and Portuguese and some Moroccan communities, these are recited only in long Tachanun. In this prayer several sins are mentioned and the heart is symbolically struck with the right fist during mention of each sin. This is followed by the mention of God's thirteen attributes of mercy. By and large, Sephardim do not rest their head on their hand for Kabbalistic reasons, but Spanish and Portuguese Jews and some Moroccans, who never accepted many Kabbalistic customs, do rest their head on their hand.
Short Tachanun
In most Nusach Ashkenaz communities, Tachanun begins with introductory verses from II Samuel (24:14), and then continues with a short confession that we have sinned and God should answer our prayers, followed by Psalm 6:2-11, which King David composed - according to traditional sources - while sick and in pain. In most Nusach Sefard communities, they also recite these verses, although only after reciting Vidui and the Thirteen Attributes.
In the Sephardic rite, Italian rite and Romaniote - adopted also in some Nusach Sefard communities, including Chabad - Psalm 25 is recited as Tachanun.
In the presence of a Torah scroll, this paragraph is recited with the head leaning on the back of the left hand or sleeve (in most Ashkenazic communities, one leans on the right hand when wearing tefillin on the left).
The next paragraph, "" ("Guardian of Israel") is recited seated, but erect (some communities recite it only 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; others (especially those who don't recite שומר ישראל on a daily basis) remain seated but erect for this passage. Tachanun is invariably followed by "half kaddish" at Shacharit and by "full kaddish" at Mincha and in Selichot.
Long Tachanun
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. On Monday and Thursday mornings, therefore, a longer prayer is recited. The order differs by custom:
In Nusach Ashkenaz, a long prayer beginning "ve-hu rachum" is recited before niflat apayim. After Psalm 6, a few stanza with a refrain "Hashem elokey Yisra'el" is added. The service then continues with Shomer Yisra'el (in some communities this is recited only on Fast Days) and Tachanun is concluded as normal. In some Nusach Ashkenaz communities, especially in Israel, they have adopted the Sephardic custom to recite Vidui and Thirteen Attributes at the beginning of long Tachanun; in some of these places, this is omitted during the Selichot season during which Vidui and Thirteen Attributes were recited right before the service, so they revert to the older custom of not reciting it.
In Nusach Sefard, the order is Vidui, Thirteen Attributes, nefilat apayim, "ve-hu rachum", "Hashem elokey Yisra'el", Shomer Yisra'el, and Tachanun is concluded as normal.
In the Sephardic rite, there are two variations: The older custom (maintained by Spanish and Portuguese and some Moroccan Jews) is to recite the Thirteen Attributes, "Anshei Amanah Avadu" (on Monday) or "Tamanu me-ra'ot" (on Thursday), another Thirteen Attributes, "al ta'as imanu kalah", Vidui, "ma nomar", another Thirteen Attributes, "ve-hu rachum", nefilat apayim, "Hashem ayeh chasadech ha-rishonim" (on Monday) or "Hashem she'arit peletat Ariel" (on Thursday), and Tachnun is concluded as on other days.