Siman 22כ״ב
1 א

לְאַחַר הַשְּׁמֹנֶה עֶשְׂרֵה, אוֹמְרִים תַּחֲנוּן בִּנְפִילַת אַפַּיִם, וְאֵין לְדַבֵּר שִׂיחַת חֻלִּין, בֵּין שְׁמֹנֶה עֶשְׂרֵה לְתַחֲנוּן.

Preface
Concerning his many prayers, Moses said of himself: 1) וָאֵשֶׁב בָּהָר אַרְבָּעִים יוֹם—"I sat on the mountain for forty days…" (Deut. 9: 9), 2) וְאָנֹכִי עָמַדְתִּי בָּהָר — "I stood on the mountain …" (Ibid. 10: 10), 3) וָאֶתְנַפַּל לִפְנֵי ה׳ —"I prostrated myself before Adonoy." Jews, symbolically, also assume these three positions during prayer by: 1) sitting before the Amidah (Shemoneh Esrei), 2) standing during the Amidah and 3) נְפִילַת אַפַּיִם (lit. falling on the face) after the Amidah. This is called tachanun (Supplication). (Based on Tur 131).Originally nefilas apayim was performed by entirely prostrating one's body upon the ground while praying and pleading for one's needs. However, with the destruction of the Temple this practice was discouraged. Also, the Talmud (Megillah 22a) states that only a righteous person comparable to Joshua, who is assured of a response to a prayer in this manner, may assume this position in prayer.Therefore, the custom has become to perform nefilas apayim only perfunctorily by sitting and tilting one's head downward (Aruch Hashulchan 131: 4).
Upon completing the shemoneh esrei, tachanun is said with nefilas apayim (falling on the face). Idle talk1I.e. any conversation not relevant to the tefillah. is prohibited between shemoneh esrei and tachanun.

2 ב

בְּשַׁחֲרִית, כֵּיוָן שֶׁיֵּשׁ תְּפִלִּין בִּשְׂמֹאלוֹ, נוֹטִין עַל צַד יָמִין, מִשּׁוּם כְּבוֹד הַתְּפִלִּין, וּבְמִנְחָה, נוֹטִין עַל צַד שְׂמֹאל.

During the shacharis [morning prayers] when tefillin are worn on the left hand, [tachanun is said] leaning on the right [hand] out of respect for the tefillin.2It is disrespectful to lean your head on the tefillin retzuos (straps) which are wound around your left arm. But at the minchah prayers the leaning is on the left [hand].

3 ג

נְפִילַת אַפַּיִם יֵשׁ לִהְיוֹת מְיֻשָּׁב, אַךְ בִּשְׁעַת הַדְּחַק יוּכַל לִהְיוֹת גַּם מְעֻמָּד. לְאַחַר תַּחֲנוּן אוֹמְרִים וַאֲנַחְנוּ לֹא נֵדַע, וְיֵשׁ לְאָמְרוֹ בִּישִׁיבָה, וְאַחַר כָּךְ עוֹמְדִין וְאוֹמְרִים מַה נַּעֲשֶׂה וְכוּ'.

Nefilas apayim is preferably done while sitting. But, when necessary it may be done while standing. After tachanun Ve'ananchnu lo neida is said. It is preferable that it be said while sitting, afterwards you should stand [and continue] saying: mah na'aseh

4 ד

אֵין נְפִילַת אַפַּיִם כִּי אִם בְּמָקוֹם שֶׁיֵּשׁ שָׁם סֵפֶר תּוֹרָה, אֲבָל בְּמָקוֹם שֶׁאֵין שָׁם סֵפֶר תּוֹרָה אַף עַל פִּי שֶׁיֵּשׁ שָׁם שְׁאָר סִפְרֵי קֹדֶשׁ, אֵין נוֹפְלִין עַל פְּנֵיהֶם, אֶלָּא אוֹמְרִים אֵת הַמִּזְמוֹר בְּלִי נְפִילַת אַפַּיִם. וּכְשֶׁמִּתְפַּלְּלִים בְּעֶזְרַת בֵּית הַכְּנֶסֶת, וּפֶתַח בֵּית הַכְּנֶסֶת פָּתוּחַ, נֶחְשָׁב כְּאִלּוּ הָיָה שָׁם סֵפֶר תּוֹרָה.

Nefilas apayim is done only in a place where a Seifer Torah is present. Where there is no Seifer Torah, even though there are other sacred books there, nefilas apayim is not done but, instead, the psalm is said without nefilas apayim. When praying in the synagogue vestibule and the door to the synagogue is open, it is considered as if the Seifer Torah is there.3And nefilas apayim is done.

5 ה

כְּשֶׁמִּתְפַּלְּלִין בְּבֵית אָבֵל, אוֹ בְּבֵית הַמֵּת אַף עַל פִּי שֶׁאֵין שָׁם אָבֵל, אֵין אוֹמְרִים תַּחֲנוּן ז' יְמֵי אֲבֵלוּת אֲפִלּוּ בְּמִנְחָה שֶׁל יוֹם ז'. וְנוֹהֲגִין שֶׁגַּם בְּשׁוּבָם לְבֵיתָם אֵינָם אוֹמְרִים. וְאִם יֵשׁ אָבֵל בְּבֵית הַכְּנֶסֶת, אֵין הַצִּבּוּר נִגְרָרִין אַחֲרָיו, וְאוֹמְרִים תַּחֲנוּן, אֶלָּא שֶׁהָאָבֵל אֵינוֹ אוֹמֵר.

When praying in the house of a mourner or in the house of the deceased, even if there is no mourner present,4If the deceased left no mourners it is customary for ten persons to gather daily at the deceased’s home and pray. (Shulchan Aruch, Yoreh Deah 376:3). tachanun is not said during the seven days of mourning, even at minchah of the seventh day. It is customary, that even if the mourners return home they do not say Tachanun. If a mourner is present in the synagogue [during prayers] the congregation is not drawn after him and they do say tachanun, whereas, the mourner, does not.

6 ו

אֵין אוֹמְרִים תַּחֲנוּן בְּבֵית הַכְּנֶסֶת שֶׁיֵּשׁ שָׁם מִילָה, אוֹ שֶׁהַבַּעַל בְּרִית אוֹ הַסַּנְדָּק, אוֹ הַמּוֹהֵל מִתְפַּלְּלִים שָׁם, אַף שֶׁהַמִּילָה תְּהֵא בְּבַיִת אַחֵר. וְאִם מִתְפַּלְּלִין מִנְחָה, בְּבֵית הַתִּינוֹק קוֹדֵם סְעֻדַּת הַבְּרִית, אוֹ בְּאֶמְצַע הַסְּעֻדָּה, גַּם כֵּן אֵין אוֹמְרִים. אֲבָל אִם מִתְפַּלְּלִים לְאַחַר בִּרְכַּת הַמָּזוֹן, אוֹמְרִים. אַךְ הַבַּעַל בְּרִית וְהַסַּנְדָּק וְהַמּוֹהֵל לֹא יֹאמְרוּ אַף לְאַחַר בִּרְכַּת הַמָּזוֹן, מִשּׁוּם דְּיוֹם טוֹב שֶׁלָּהֶם הוּא.

Tachanun is omitted in a synagogue where a circumcision will take place, or if the father of the child to be circumcised, or the sandik who holds the child at the circumcision; or the mohel5The mohel is the one who performs the circumcision. is praying there, even if the circumcision will take place at another location. If the minchah prayer is said, in the child's home, before the bris6Bris—circumcision. feast or during the feast [there,] too, [tachanun] is omitted. But, if [the mincha] prayer is said after birkas hamazon7Birkas hamazon—grace after the meal. [tachanun] is said. However, the father of the child, the one holding the child and the mohel do not say [tachanun] even after birkas hamazon because it is their holiday8And tachanun is not said on festive days. See para. 8.

7 ז

וְכֵן אֵין אוֹמְרִים, בְּבֵית הַכְּנֶסֶת שֶׁיֵּשׁ שָׁם חָתָן, כָּל שִׁבְעַת יְמֵי מִשְׁתֶּה שֶׁלּוֹ, אִם הֶחָתָן הוּא בָּחוּר אוֹ הַכַּלָּה בְּתוּלָה. אֲבָל אַלְמָן שֶׁנָּשָׂא אַלְמָנָה, אֵין לוֹ רַק שְׁלשָׁה יָמִים וְאַחַר כָּךְ אוֹמְרִים. וּבְיוֹם הַחֻפָּה בְּשַׁחֲרִית אוֹמְרִים, וּבְמִנְחָה שֶׁהוּא סָמוּךְ לַחֻפָּה אֵין אוֹמְרִים (קל"א).

Likewise, [tachanun] is omitted in a synagogue where a groom is present, during all seven days of feasting, provided that the groom was a bochur9I.e. never previously married. or the bride a besulah.9I.e. never previously married. But if a widower married a widow there are only three days,10That tachanun is omitted. after which [tachanun] is resumed. On the day of the marriage ceremony [tachanun] is said at shacharis11Others disagree and maintain the tachanun is omitted at shacharis as well as minchah. (Halachos ketanos I, 21). prayers, but at the minchah preceeding the ceremony it is not said.12If the groom is present at the start of the prayers and left before the congregation reached tachanun, nevertheless, tachanun is omitted.

8 ח

אֵין אוֹמְרִים תַּחֲנוּן לֹא בְּרֹאשׁ חֹדֶשׁ וְלֹא בַּחֲמִשָּׁה עָשָׂר בְּאָב, וְלֹא בַּחֲמִשָּׁה עָשָׂר בִּשְׁבָט וְלֹא בַּחֲנֻכָּה וְלֹא בְּפוּרִים גָּדוֹל בּ' יָמִים, וְלֹא בְּפוּרִים קָטָן בּ' יָמִים, וְלֹא בּל"ג בָּעֹמֶר, וְלֹא בְּכָל חֹדֶשׁ נִיסָן, וְלֹא בְּתִשְׁעָה בְּאָב, וְלֹא בַּיָּמִים שֶבֵּין יוֹם כִּפּוּר לְסֻכּוֹת, וְלֹא מֵרֹאשׁ חֹדֶשׁ סִיוָן עַד לְאַחַר אִסְרוּ חַג דְּשָׁבוּעוֹת וְלֹא בְּאִסְרוּ חַג דְּסֻכּוֹת, בְּכָל אֵלּוּ אֵין אוֹמְרִים בְּמִנְחָה שֶׁלִּפְנֵיהֶם, אֲבָל בְּעֶרֶב רֹאשׁ הַשָּׁנָה וּבְעֶרֶב יוֹם הַכִּפּוּרִים אוֹמְרִים בַּמִנְחָה שֶׁלִּפְנֵיהֶם. וּבְעֶרֶב רֹאשׁ הַשָּׁנָה אוֹמְרִים גַּם בַּסְּלִיחוֹת רַק לְאַחַר כָּךְ אֵין אוֹמְרִים.

Tachanun is not said on the following days: Rosh Chodesh, the fifteenth of Av,13At one time observed as a festival for the numerous wonderful events of this day: 1) The day that God’s decree that 600,000 of those that came into the wilderness shall die before the Jews enter Eretz Yisrael, ended. 2) The day that it became permissible for Jewish women to marry into other tribes of Israel (see Numbers 36:6–9). Also it was the day that the Tribe of Benyamin was again permitted to intermarry with the other tribes of Israel, after being ostracized for a period of time. 3) Jerobaam, the king, had posted soldiers for many years not allowing the Jews their pilgrimages to Jerusalem for the Three Festivals. Hosea, King of Israel, opened the roads to Jerusalem on Av 15. 4) When the Second Temple was completed the land was totally desolate, so much so, that no wood could be found for burning on the Altar. Many Jews jeopardized their lives and disobeyed the authorities and brought wood for the Altar. The day when cutting this wood was completed was Av 15. the fifteenth of Shevat,14The New Year for the fruits of trees, i.e. the determinant as to which year’s tithes one is obligated to donate each year is Shevat 15. during Chanukah, the two days of greater Purim,15I.e. Purim and Shushan Purim. the two days of minor Purim,16When there is a leap year in the Hebrew calendar and an extra month—Adar I is added, then Greater Purim is celebrated on 14 and 15 Adar II and the Minor Purim during Adar I. the thirty-third day of the Omer,17The day that the plague that decimated Rabbi Akiva’s disciples ended. during the entire month of Nissan,18The month of the Exodus and the Pesach observance. Tishah Be'Av,19The day of the destruction of both Temples, which will become a joyous holiday when the Mashiach comes. the days between Yom Kippur and Sukkos, from Rosh Chodesh Sivan until the day following the day after Shavuos,20The days of preparation for and receiving of the Torah at Mount Sinai. the day following Succos.21The day following a festival is still somewhat festive. On all these days tachanun is also not said at minchah on the preceeding days. However, on the day before erev Rosh Hashanah, and on the day before erev Yom Kippur, Tachanun is said at Minchah. On the day before Rosh Hashana [tachanun] is said at selichos, but after that22I.e. at Shacharis of Erev Rosh Hashanah. [tachanun] is omitted.

9 ט

בְּשֵׁנִי וּבַחֲמִשִּׁי לְפִי שֶׁהֵם יְמֵי רָצוֹן, כִּי בְּאַרְבָּעִים יוֹם שֶׁל קַבָּלַת לוּחוֹת שְׁנִיּוֹת, עָלָה מֹשֶׁה רַבֵּנוּ בְּיוֹם ה', וְיָרַד בְּיוֹם בּ', לָכֵן מַרְבִּים בָּהֶם תַּחֲנוּנִים, וְאוֹמְרִים קוֹדֶם תַּחֲנוּן, וְהוּא רַחוּם, וְאוֹמְרִים אוֹתוֹ מְעֻמָּד, וְצָרִיךְ לְאָמְרוֹ בְּכַוָּנָה, וּבִמְתִינוּת, דֶּרֶךְ תַּחֲנוּנִים. וּבְיָמִים שֶׁאֵין אוֹמְרִים תַּחֲנוּן אֵין אוֹמְרִים אוֹתוֹ.

On Mondays and Thursdays, are especially favorable days [for prayer] because during the forty days the second luchos23Luchos—the tablets upon which the Ten Commandments were inscribed. were received, Moses ascended on a Thursday and descended on a Monday,24And it was during those forty days that Moses begged and pleaded for forgiveness for the sin of the golden calf. therefore, additional supplications are recited and before tachanun, vehu rachum is said.25The custom of Nusach Sefard is to say tachanun before vehu rachum. It (vehu rachum) is said standing. It must be said with concentration and with deliberation in a pleading manner. On days when tachanun is omitted it (vehu rachum) is not said.

10 י

לְאַחַר תַּחֲנוּן אוֹמְרִים חֲצִי קַדִּישׁ. וּבְשֵׁנִי וּבַחֲמִשִּׁי אוֹמְרִים, אֵל אֶרֶךְ אַפַּיִם [מְעֻמָּד]. וְעַיֵּן לְקַמָּן סִימָן כ"ה סָעִיף ב', מָתַי אֵין אוֹמְרִים אוֹתוֹ (שם ובעט"ז מ' קל"ב).

After tachanun [is completed] half-kaddish26“Half-Kaddish—from Yisgadal until de’amiron be’alma ve’imru amein. is said. On Mondays and Thursdays Keil erech apayim27A short prayer said before removing the Seifer Torah from the ark. is said while standing.