3. Tachanun:[1]

Shul in which the Bris will be taking place:[2] Tachanun is omitted in the Shul in which a Bris will be taking place that day, as the Mitzvah of Mila was accepted with joy.[3] [This applies even if none of the Baalei Bris will be Davening in the Minyan.[4]] It is not omitted from any other Shul in the community.

Baal Bris present during Minyan:[5] Tachanun is omitted in a Minyan in which the Baal Bris [i.e. father of child or Mohel, or Sandek[6]] is participating in, even if the Bris will not be taking place in that Shul.

After the Bris: Some Poskim[7]  rule that Tachanun is recited in the Mincha prayer if it is taking place after the Bris. This applies even in the Shul in which the Bris took place and even if the Baal Bris is present by the Minyan and even if the baby is still present. Other Poskim[8], however, rule that Tachanun is omitted in the Mincha prayer even if it is taking place after the Bris, if it takes place near the child [i.e. in the room in which the baby is present]. However, in another area not near the child, Tachanun is to be recited even if the Baal Bris is present by the Minyan.[9] Some Poskim[10] arbitrate that if Mincha is prayed in middle of the meal prior to Birchas Hamazon, then Tachanun is to be omitted while if it is Davened after the meal, then it is to be recited. Other Poskim[11], however, negate this.

The Baal Bris:[12] The Baalei Bris themselves do not recite Tachanun neither in Shacharis or Mincha on the day of the Bris, as it is their holiday. This applies even after the Bris has already taken place.

Lamnatzeiach: The Ashkenazi custom is to recite Lamnatzeiach in Shacharis even when a Bris will be taking place in the Shul, or a Baal Bris is present.[13] Practically, according to Chabad custom, whenever Tachanun is omitted from Shacharis, Lamnatzeiach is likewise omitted, including on the day of a Bris.[14]

Keil Erech Apayim:[15] The prayer of Keil Erech Apayim is to be recited even on days that Tachanun is omitted, with exception to a certain list of days.[16] Thus, it is recited even if there is a Bris taking place in Shul. [Practically, however, the widespread Chabad custom today is not to recite it on any day that Tachanun is omitted. Customarily, it is thus omitted if a Bris is taking place in Shul.[17] However, the Rebbe’s personal custom was to say Keil Erech Apayim even on days that Tachanun is omitted, with exception to the list of days brought above.[18] Likewise, it is quoted that the Rebbe directed not to change from the above-mentioned ruling to say Keil Erech Apayim even on days that Tachanun is omitted, with exception to the days listed above.[19] Some Rabbanim[20] profess following the original custom, while others[21] say that the latter custom is to be followed.]

Shabbos:[22] When a Bris is taking place on Shabbos, the prayer of Av Harachamim is omitted.

[1] See Admur 131:5-6; Siddur Admur; Rama 131:1; Michaber O.C. 131:4; Y.D. 265:13; Ketzos Hashulchan 24:5; Shevach Habris 13; Piskeiy Teshuvos 131:17-19; See Pesakim Uteshuvos 265:44-45; See Encyclopedia Talmudit Vol. 4 Erech Bris Mila p. 248 footnotes 32-36

[2] Admur 131:5; Siddur Admur; Michaber ibid; Rama ibid; Shibbulei Haleket 30; See Shabbos 130a; See Pesakim Uteshuvos 265:44

[3] Furthermore, being that it is a time of happiness and that everyone is in a state of joy, it arouses the attribute of mercy above similar to Shabbos and Yom Tov, and therefore we do not recite Tachanun in order not to arouse the attribute of judgment during the time of divine compassion.

[4] M”B 131:22

[5] Admur 131:6; M”A 131:11; Kneses Hagedola 131; Derech Hachaim 38:8; Kitzur SHU”A 22:6; M”B 131:22

[6] Derech Hachaim ibid; Kitzur SHU”A ibid; M”B ibid; See Michaber 559:8-9; Rama 559:8; M”A 559:12

[7] 1^st opinion in Admur 131:6; Rama ibid; Levush 131; Directive of Rebbe to Rav Leibel Bistritzky, brought in Hiskashrus

[8] 2^nd opinion in Admur 131:6; Taz 131:11; M”A 131:11; Bach 131 in name of Rashal; Ketzos Hashulchan 24:5; Toras Menachem 2:282; Shevach Habris 13:2 footnote 7; Hiskashrus 590:16

[9] Admur ibid

[10] Elya Raba 131:11; Chayeh Adam; Derech Hachaim Kitzur SHU”A; M”B 131:25

[11] P”M 131 M”Z 11

[12] Chayeh Adam 32:33; Hashlama of Admur 131:6; Kitzur SHU”A 22:6; Ketzos Hashulchan 24:5; See Beis Yosef 559:9; Zohar 1:95; Shevach Habris 132; See Pesakim Uteshuvos 265:45

[13] Admur 602:4; Rama O.C. 131:1; Y.D. 265:13 [regarding Keil Erech Apayim]; Shach 265:24; Rokeiach 113; Maharam Mintz; Maharil

The reason: Due to the pain of the child. [Rama ibid]

[14] Siddur Admur

The reason: As the day of the circumcision is a day of joy and not a day of oppression. [Shach 265:24 in name of Abudarham and Kol Bo]

^[15] See Divrei Nechemia 131:9; Otzer Minhagei Chabad Tishreiy p. 166; Siddur of Rav Raskin; Koveitz Hearos Ubiurim 738:73; 743:78; 746:91; 915:88; 922:226

Background from Divrei Nechemia: The Divrei Nechemia 131:9 brings three opinions regarding the saying of Keil Erech Apayim:1) It is only omitted by a day that Hallel is recited or a day that has the status of a Yom Tov like Erev Pesach. [This is the opinion of the Rama 429:2] 2) It is omitted on every Erev Yom Tov and on Isru Chag. 3) Every day that Tachanun is omitted so is Lamnatzeiach. [So rules Peri Chadash 131] The Divrei Nechemia concludes that by Lamnatzeiach we rule like the third opinion, however by Keil Erech Apayim we rule like the opinion who rules it is to be recited. The Ketzos Hashulchan 25:1 rules that it is to be recited when a Chasan is present.

[16] Admur 429:12 “Throughout the month, although Tachanun is not recited, we do recite Keil Erech Apayim on Mondays and Thursdays.”; 602:4 “If there is a Bris between Rosh Hashanah and Yom Kippur, Tachanun is not recited, although (Keil Erech Apayim is recited)”; Siddur Admur “Erech Apayim is omitted on the following list of days..”; Implication of Rama 429:2; Darkei Moshe 602; Minhagim Tirana p. 167; Maharil Minhagei Chodesh Nissan; Divrei Nechemia 131:9; Kaf Hachaim 602:12; Ketzos Hashulchan 25:1; Sefer Haminhagim p. 13 quotes the ruling in Siddur ibid

Background of ruling of Admur: In the Shulchan Aruch [429:12; 602:4] Admur rules that Keil Erech Apayim is recited even on days that Tachanun is omitted, and so is likewise the ruling of Admur in his Siddur. [Some explain that Admur in 602:4 placed this ruling in parentheses being that it is not brought in previous Poskim in Shulchan Aruch. [Shulchan Menachem ibid footnote 2] Vetzaruch Iyun as it is brought by Admur in 429:12 without parentheses, and is likewise clearly implied from the Rama 429:2] 

[17] Sichas Bilti Mugah 6^th Tishrei 1975 5, printed in Sichos Kodesh 4735 1:48-49, that the Rebbe equates Keil Erech Apayim with Lamnatzeiach , that it is to be omitted on days that Tachanun is omitted; Practical directive printed in Siddur Tehillas Hashem in editions from 1978 and onwards with the Rebbe’s approval [See Hearos Ubiurim 746:91 for the Maaneh Kesav Yad; Igros Kodesh vol. 33; See also Hiskashrus 86:18 footnote 6]; Article of Rav Leibal Groner in Hearos Ubiurim 915:88 that the Rebbe instructed for it to be omitted; See Shulchan Menachem 3:293; Glosses of Rav Raskin p. 165; Hiskashrus 438 p. 17

The reason behind the Rebbe’s ruling: The Rebbe explains that the ruling in the Shulchan Aruch of Admur follows the ruling of the Rama that differentiates between the laws of Tachanun and that of Lamnatzeiach. However according to Admur in the Siddur that rules Lamnatzeiach is always omitted when Tachanun is not said then likewise Keil Erech Apayim is to be omitted in all days that Tachanun is not said. [Sichas Kodesh ibid, printed in Shulchan Menachem ibid] As for the reason why Keil Erech Apayim is omitted this is because it mentions sin, and we do not desire to mention sin on any day that Tachanun is omitted. [See Shaar Hakolel 36:2; Shulchan Menachem ibid footnote 5] The major question on this Sicha is that it contradicts the explicit ruling of Admur in the Siddur regarding Keil Erech Apayim. Some want to suggest that perhaps indeed the ruling in the Siddur is not from Admur. Others suggest that the Sicha is Bilti Mugah and hence unreliable; Vetzaruch Iyun. See Koveitz Hearos Ubiurim 738:73

[18] Glosses of Rav Raskin p. 165; Minhagei Melech p. 31; Rav Mondshine in Hearos Ubiurim 746; In Nissan 5748 the Rebbe was witnessed to say Keil Erech Apayim on Monday’s and Thursdays

[19] See Hearos Ubiurim 922:226 that Rav Y.L. Groner stated at the time of the Sicha that the Rebbe explicitly told him not to swerve from the ruling of the Siddur; See Hiskashrus 86:18 footnote 6 that the Rebbe told Rav Groner not to add the above statement to Sefer Haminhagim p. 13 which quotes the ruling of Admur in the Siddur ibid

[20] Rav Baruch Oberlander; Rav S.B. Levin

[21] Rav Raskin

[22] Admur 284:14; Rama 284:7