Halachos Of Chazoras Hashatz
 
1029. One is not permitted to speak anytime during Chazoras Hashatz, and the Shulchan Aruch states that "one who does speak is a grave sinner and his sin is too great to bear". This is the only place in all of Shulchan Aruch that such a severe language is used. Shulchan Aruch w/Mishnah Brurah 124:4,7
 
1030. Rabbeinu Yonah (one of the Rishonim) states that one who speaks during Chazoras Hashatz is equivalent to one who murders his brother, as we find the Torah says about Kayin who killed his brother Hevel "his sin is too great too bear", just as the Shulchan Aruch says about one who speaks during Chazoras Hashatz. Piskei Tshuvos 124:7, Orchos Chaim, Hogein Derech Moshe Yom9
 
1031. The difficulties that one experiences in life with regard to children, health and parnassah derive from the sin of speaking during Tefillah. Piskei Tshuvos 124:7, Igeres R' Dov Ber, son of The Shulchan Aruch Harav
 
1032. When one speaks during during Chazoras Hashatz, not only has one caused that his own tefillos will not be accepted, but one has caused that the tefillos of others will also not be accepted. Therefore, if one knows himself; that he will be unable to remain silent, it is better that he should not come to shul at all, rather than be "a sinner who causes others to sin". Piskei Tshuvos 124:7, Yaaros Dvash Drush7, Olelos Efraim vol4pg3, Pesach Aneiyim L'Hachidah
 
1033. One who speaks during Chazoras Hashatz causes the Shechinah to leave Klal Yisroel, and it is as if he has sinned with Avodah Zorah. Drush Chasam Sofer vol2pg309b
 
1034. The father of the Shelah Hakodosh states that "I swear, amongst all sins I have not found any as terrible as one who speaks in shul purposely and thereby humiliates the honor of God, and he is as bad as Yeravam ben Nevat who sinned (with Avodah Zorah) and caused others to sin, and this sin holds back the coming of Moshiach". Piskei Tshuvos 124:7, Sefer Yesh Nochalin
 
1035. The Elya Rabba citing the Kol Bo states: "Many shuls have been destroyed directly as a result of this sin {speaking during Chazoras Hashatz and tefillah}. Shulchan Aruch w/Mishnah Brurah 124:7 MB27
 
1036. The magnitude of the sin of speaking during Chazoras Hashatz is applicable as well to one who speaks during Krias Hatorah, or any other time during Tefillah when one may not speak, because one who conducts his own private conversation while the tzibbur is gathered to speak with God declares that he is not interested in the honor of God's kingdom, and that he has no portion in the God of Israel. Piskei Tshuvos 124:7, SA 146:2
 
1037. The sin of speaking during Chazoras Hashatz (or Krias Hatorah) is so severe that the Shulchan Aruch states that one should scream at one who is sinning in this way, as follows; if the person is speaking due to inattention to the severity of the sin, or the point in davening, one should tell the person in a quiet, polite manner to refrain from talking. Shulchan Aruch w/Mishnah Brurah 124:7, Piskei Tshuvos 124:7, S'U Shevet Halevi 10:13
 
1038. However, if the person does not accept the rebuke and continues to speak, or it is a person who has repeated this sin many times after rebuke, he should be dealt with severely, (in accordance with the directive of the Rambam in Hilchos Deios 6:7), as follows;
 
a) First, speak to the person privately {after davening}, pleasantly and in a gentle manner, explaining the great loss caused by speaking during davening, and the immense reward for doing Teshuvah and refraining from talking in the future.
 
b) If unsuccessful, and the person continues to repeat this sin this process should be repeated once more.
 
c) If still unsuccessful, and the person  continues to repeat this sin one should berate and embarrass the person publicly, publicize his sin, shame him to his face, and curse him, until he does Tshuvah from this sin.
 
d) If still unsuccessful, and the person continues to speak during davening he should be barred from entering the shul in order to prevent him from causing others to sin as he has.
 
Due to the great danger involved in publicly embarrassing another Jew, one should never undertake the implementation of the above without the specific guidance of a Rov/Posek.
 
Shulchan Aruch w/Mishnah Brurah 124:7, Piskei Tshuvos 124:7, S'U Shevet Halevi 10:13

1039. During Chazoras Hashatz (the repetition of the silent Shmona Esrei by the Chazzan) one must remain silent, follow the Shmona Esrei in a siddur, concentrate on the berachos being said, and answer Boruch Hu U'Voruch Shemo and Amein to each Beracha. Shulchan Aruch w/Mishnah Berurah 124:4,7
 
1040. One may not say Tehillim or other prayers, or learn Torah during Chazoras Hashatz. Shulchan Aruch w/Mishnah Berurah 124:4
 
1041. One who learns Torah or says Tehillim or other prayers during Chazoras Hashatz is not making a "Nachas Ruach" (pleasure) to Hashem with the tefillah or learning and Hashem does not desire it. Kaf Hachaim 124:16, Piskei Tshuvos 124:8
 
1042. Likewise, one should refrain from doing anything during Chazoras Hashatz including a Mitzvah. If one wishes to give Tzedakah, one should prepare the coins/bills in advance in order not to lose concentration of the berachos being said. Shulchan Aruch w/Mishnah Brurah 566:MB12, S'U Be'er Moshe 8:42
 
1043. If a Rov is approached with a Shailah during Chazoras Hashatz; if before the end of the beracha of Ha'kail Hakodosh he should refrain from answering any Shailah (other than Pekuach Nefesh); if after Ha'kail Hakodosh he is permitted and obligated to answer a Shailah that cannot wait until after tefillah. However, he should preferably leave the room to answer the Shailah. Aruch Hashulchan 124:12, Piskei Tshuvos 124:8
 
1044. One may not remove one's tefillin or put on Rabbeinu Tam tefillin during Chazoras Hashatz. Shulchan Aruch w/Mishnah Berurah 34:14
 
1045. Even if there is a minyan who are listening to Chazoras Hashatz, one is obligated to listen carefully and answer to all the berachos because it is an individual obligation upon each person. Igros Moshe OC4:19, Piskei Tshuvos 124:8, Tshuvos V'Hanhagos 1:106
 
1046. Even if one missed a portion of Chazoras Hashatz one is obligated to listen carefully to the rest of it and answer to the berachos. Halichos Shlomo 9:3, Piskei Tshuvos 124:8
 
1047. If the Chazzan is singing during Chazoras Hashatz (while not saying the words of Shmona Esrei), or is saying Piyuttim (as on Rosh Hashanah/Yom Kippur) one is permitted to look at and think in Torah but not speak (while being careful to answer BHUS and Amein to each beracha). Piskei Tshuvos 124:8fn80, Shleimas Chaim 131, see also Shulchan Aruch w/Mishnah Berurah 68:1MB3
 
1048. However, during Kaddish one may not even look at Torah (even while the Chazzan is singing) because one must concentrate on the Kaddish. Shulchan Aruch w/Mishnah Berurah 68:1MB3
 
1049. The Ramah cites an opinion that one should stand during the entire Chazoras Hashatz. Shulchan Aruch w/Mishnah Brurah 124:4
 
1050. However according to many Poskim this custom is only a Chumrah (stringency), and one is not obligated to stand; while those who do stand are praiseworthy. Certainly those who are weak and elderly need not strain themselves to stand. Piskei Tshuvos 124:10, S'U Halochos Ketanos 2:80, Halichos Shlomo 9:35, S'U Yechave Da'as 5:11
 
1051. Even if one is not standing for Chazoras Hashatz, one must stand up for Modim because one must bow at Modim, and one cannot bow from a sitting position. Shulchan Aruch w/Mishnah Brurah 94:5, 127:1, Piskei Tshuvos 127:2