This article is an excerpt from our Sefer
Buy me here or on Amazon.com
Bris Mila on Rosh Hashanah:
When to make a circumcision: In the event that a Bris Mila falls out on Rosh Hashanah, then if it is planned to take place in Shul, it is to be done after the Torah reading, before the blowing of the Shofar. However if the Bris is planned to take place outside Shul, then it should be done after the prayers have completed [unless the house is near the Shul and it will not cause a great interval]. [When the Bris is taking place in Shul, prior to Tekios, the wine is to be given to a child that has reached the age of Chinuch to drink. The meal however is to take place after the completion of Davening.]
May one delay the circumcision until after Davening if he desires guests from other shuls to attend?
Some Poskim rule that if delaying the Bris will allow a larger participation, it is permitted to delay it, as G-d is glorified within a larger audience.
Is the Mohel to clean his lips prior to blowing Shofar if he is also the Baal Tokeia?
Some Poskim rule that if the Mohel is also the Baal Tokeia then he is not to clean his lips of the blood in order to mix the Mitzvah of Mila with the Mitzvah of Shofar. Other Poskim however negate this practice under the claim that the blood forms a Chatzitza between the lips and the Shofar. Practically if there remains only a little amount of blood in the mouth and lips it is not a Chatzitza. Nevertheless he should wipe the blood off the external part of his lips out of respect for the Mitzvah.
When is the Mila to take place if Rosh Hashanah falls on Shabbos?
Is one to have a full meal in honor of the Bris?
Some have the custom to have a small Kiddush with Mezonos after the Bris rather than a large meal in order to prevent any lax activity on the holy day. Many however are accustomed to have a regular Bris meal with bread for the family and close friends.
Naming the child:
Some have the custom of naming the child “Yitzchak” when the Bris is taking place on Rosh Hashanah in honor of Yitzchak Avinu who is remembered on this day.
Must a Mohel travel to an area without a Minyan and Shofar in order to perform a Bris on Rosh Hashanah?
 584/9; Michaber 584/4
 The reason: We do not delay until after the prayer to do the Bris as Zerizin Makdimim Lemitzvos. Rather it takes place after the Torah reading, prior to the Shofar blowing, in order to proximate the Bris of Avraham to Akeidas Yitzchak, as Hashem remembers Akeidas Yitzchak when the Shofar is blown. [ibid; Levush; Beis Yosef in name of Terumas Hadeshen 266] The Levush explains that due to the Mitzvah of Zerizin Makdimin one is to have the Mila take place before midday and if we delayed the Mila until after Davening it would be delayed past midday. Another reason recorded is because the Shechina resides during the Torah reading and we desire the Shechina to reside also on the child. [Rokeiach 217 brought in Beis Yosef ibid] Another reason is in order not to make an interval between the Tekios of Meumad and Meyushav. [Kaf Hachaim 584/27] Another reason is because the Mitzvah of Mila is Tadir. [Gr”a; M”B 584/11]
 Admur ibid; Kneses Hagedola brought in M”A 584/7; M”B 584/11
 M”E 584/26; M”B 584/11; Kaf Hachaim 584/28
 Piskeiy Teshuvos 584/5 in name of Rav SZ”A
 Kneses Hagedola 584; Kaf Hachaim 584/28
 Rav Faivesh of Krakow brought in Taz 584/2
 Degul Merivava brought in Shaareiy Teshuvah 584/4
 See Shaareiy Teshuvah ibid; Kaf Hachaim 584/29
 M”E 584/27; M”B 584/12; Kaf Hachaim 584/29
 See Kaf Hachaim 584/31
 Levush 584; M”A 584/7
 Elya Raba 595/2 brought in Shaareiy Teshuvah 584/4
The reason: In order to proximate the Mila to the Torah reading and in order not to make an interval between Ashrei and the Kaddish. [ibid]
 Yaavetz in Siddur; Derech Hachaim; Mateh Efraim 584/26; M”B 584/12
 Mateh Efraim 596/5
 Ketzei Hamateh ibid; Piskeiy Teshuvos 584/5
 See Leket Yosher p. 52 that the Terumos Hadeshen told someone to name his child after Yitzchak and not after his grandfather being that he and his grandfather are obligated in the honor of Yitzchak.
 Minchas Yitzchak 2/75; Orchos Chaim in name of Nachal Eshkol Mila 40; Piskeiy Teshuvos 584/5
 Sdei Chemed R”H 2/47