Halacha

הלכה א
אָבֵל חַיָּב לִקְרֹעַ עַל מֵתוֹ שֶׁנֶּאֱמַר (ויקרא י ו) "וּבִגְדֵיכֶם לֹא תִפְרֹמוּ וְלֹא תָמֻתוּ" הָא אַחֵר חַיָּב לִפְרֹם. וְאֵין קְרִיעָה אֶלָּא מְעֻמָּד. שֶׁנֶּאֱמַר (שמואל ב יג לא) "וַיָּקָם הַמֶּלֶךְ וַיִּקְרַע אֶת בְּגָדָיו". וּמֵהֵיכָן קוֹרֵעַ. מִלְּפָנָיו. וְהַקּוֹרֵעַ מֵאַחֲרָיו אוֹ מִן הַצְּדָדִין אוֹ מִלְּמַטָּה לֹא יָצָא יְדֵי חוֹבַת קְרִיעָה. אֶלָּא כֹּהֵן גָּדוֹל שֶׁהוּא פּוֹרֵם מִלְּמַטָּה:
כסף משנה
1.
A mourner is obligated to rend his garments for his dead, as can be derived from Leviticus 10:6: "Do not rend your garments lest you die." Implied is that others must rend their garments.
One must rend one's garments only while standing, as II Samuel 13:31 states: "And the king stood and rent his garments."
Where does one rend his garment? In front. If one rends his garment from the back or from the sides or from the bottom, he does not fulfill the obligation to rend his garments, with the exception of a High Priest who must rend his garment from the bottom.

הלכה ב
כַּמָּה שִׁעוּר הַקֶּרַע. טֶפַח. וְאֵין צָרִיךְ לְהַבְדִּיל שְׂפַת הַבֶּגֶד. וּמֻתָּר לוֹ לִקְרֹעַ בִּכְלִי. וְיֵשׁ לוֹ לִקְרֹעַ בִּפְנִים שֶׁלֹּא בִּפְנֵי אָדָם. לְפִיכָךְ יֵשׁ לוֹ לְהַכְנִיס יָדוֹ בִּפְנִים וְקוֹרֵעַ בְּצִנְעָה. וְאֵינוֹ חַיָּב לִקְרֹעַ אֶלָּא בֶּגֶד הָעֶלְיוֹן בִּלְבַד:
כסף משנה
2.
What is the required measure for the tear? A handbreadth. It is not necessary to rip apart the border of the garment. One may rend his garments with a utensil.
One may rend one's garments inside, not in the presence of others. Therefore he may place his hand inside his garment and tear it modestly. He is only obligated to tear his upper garment.

הלכה ג
כָּל שִׁבְעַת יְמֵי אֲבֵלוּת הַקֶּרַע לְפָנִים וְאִם בָּא לְהַחְלִיף מַחְלִיף וְאֵינוֹ קוֹרֵעַ קֶרַע אַחֵר. שֶׁכָּל קֶרַע שֶׁאֵינוֹ בִּשְׁעַת חִמּוּם אֵינוֹ קֶרַע. בַּמֶּה דְּבָרִים אֲמוּרִים בִּשְׁאָר הַמֵּתִים חוּץ מֵאָבִיו וְאִמּוֹ. אֲבָל עַל אָבִיו וְעַל אִמּוֹ קוֹרֵעַ עַד שֶׁמְּגַלֶּה אֶת לִבּוֹ. וּמַבְדִּיל שְׂפַת הַבֶּגֶד וְאֵינוֹ קוֹרֵעַ בִּכְלִי אֶלָּא בְּיָדוֹ מִבַּחוּץ בִּפְנֵי כָּל הָעָם וְקוֹרֵעַ כָּל הַבְּגָדִים שֶׁעָלָיו. וּבֶגֶד הַזֵּעָה הַדָּבוּק לִבְשָׂרוֹ אֵינוֹ מְעַכֵּב. וְאִם הֶחְלִיף בֶּגֶד אַחֵר חַיָּב לִקְרֹעַ כָּל שִׁבְעָה. וְכֵן עַל אָבִיו וְעַל אִמּוֹ חוֹלֵץ כְּתֵפוֹ וּמוֹצִיא זְרוֹעוֹ מִן הֶחָלוּק עַד שֶׁיִּתְגַּלֶּה כְּתֵפוֹ וּזְרוֹעוֹ. וְהוֹלֵךְ כָּךְ לִפְנֵי הַמִּטָּה. וְאַחַר שֶׁיִּקָּבֵר אָבִיו וְאִמּוֹ אֵינוֹ חַיָּב לַחְלֹץ:
כסף משנה
3.
For the entire seven days of mourning, he keeps the tear in front of him. If he desires to change his garments, he may. He is not required to rend the second garment, for any tear that is not made at the time of emotional excitement, is not a tear.
When does the above apply? With regard to other deceased persons aside from his father and mother. For his father and mother, by contrast, he must rend his garment until he reveals his heart. He must rip apart the border of the garment; he may not tear it with a utensil, and must tear it outside, in the presence of people at large.
He must tear all the garments he is wearing. His underwear - i.e., the garments worn next to his flesh - need not be ripped. If he changes his clothes, he is required to rend them for all seven days. Similarly, for his father and mother, he uncovers his shoulder and takes his forearm out from his garment, revealing his shoulder and his forearm. He passes before the bier in this manner. After his father and his mother are buried, however, he is not required to uncover his shoulder.

הלכה ד
קוֹרְעִין לְקָטָן מִפְּנֵי עָגְמַת נֶפֶשׁ. וְחוֹלֶה שֶׁמֵּת לוֹ מֵת אֵין מְקַרְעִין לוֹ וְלֹא מוֹדִיעִין לוֹ שֶׁלֹּא תִּטָּרֵף עָלָיו דַּעְתּוֹ. וּמְשַׁתְּקִין אֶת הַנָּשִׁים מִפָּנָיו:
כסף משנה
4.
A child's garments should be torn to create sorrow.
When a dangerously ill person loses a close relative, we do not rend his garments, nor do we notify him lest he lose control of his emotions. We silence the women in his presence.

הלכה ה
וְקוֹרֵעַ אָדָם עַל חָמִיו וְעַל חֲמוֹתוֹ מִפְּנֵי כְּבוֹד אִשְׁתּוֹ. וְכֵן הָאִשָּׁה קוֹרַעַת עַל חָמִיהָ וְעַל חֲמוֹתָהּ מִפְּנֵי כְּבוֹד בַּעְלָהּ:
כסף משנה
5.
A person should rend his garments when his father-in-law and mother-in-law dies as an expression of honor for his wife. Similarly, a woman should rend her garments for her father-in-law and mother-in-law as an expression of honor for her husband.

הלכה ו
מִי שֶׁאֵין לוֹ חָלוּק לִקְרֹעַ וְנִזְדַּמֵּן לוֹ חָלוּק בְּתוֹךְ שִׁבְעָה קוֹרֵעַ. לְאַחַר שִׁבְעָה אֵינוֹ קוֹרֵעַ. וְעַל אָבִיו וְעַל אִמּוֹ אֲפִלּוּ לְאַחַר שִׁבְעָה קוֹרֵעַ כָּל שְׁלֹשִׁים יוֹם. וְכָל הַיּוֹצֵא בְּבֶגֶד קָרוּעַ לִפְנֵי מֵתִים כְּלוֹמַר שֶׁהוּא קָרַע עַתָּה עֲלֵיהֶן. הֲרֵי זֶה גּוֹנֵב דַּעַת הַבְּרִיּוֹת וְזִלְזֵל בִּכְבוֹד הַחַיִּים וְהַמֵּתִים:
כסף משנה
6.
When a person does not have an outer garment to tear at the time of a person's passing and he obtains a garment within the seven days of mourning, he is obligated to tear it. After seven days, he is not obligated to tear it. For his father and mother, he is obligated to tear it even if he obtains it after the seven days, but within the 30 days.
Whenever a person goes out wearing a torn garment before the dead implying that he tore the garment because of them, he is deceiving people and degrading the honor of the dead and the living.

הלכה ז
הָאוֹמֵר לַחֲבֵרוֹ הַשְׁאִילֵנִי חֲלוּקְךָ וַאֲבַקֵּר אֶת אָבִי שֶׁהוּא חוֹלֶה וְהָלַךְ וּמְצָאוֹ שֶׁמֵּת. קוֹרֵעַ וּמְאַחֶה וּמַחֲזִיר לוֹ אֶת חֲלוּקוֹ וְנוֹתֵן לוֹ דְּמֵי קִרְעוֹ. וְאִם לֹא הוֹדִיעוֹ שֶׁהוּא מְבַקֵּר לוֹ חוֹלֶה הֲרֵי זֶה לֹא יִגַּע בּוֹ:
כסף משנה
7.
When one tells a colleague: "Lend me your cloak so that I can visit my father who is dangerously ill," if, when he visits him, he finds that he died, he should rend the garment, mend it, and return it, reimbursing the owner for the tear. If he does not notify him that he is going to visit a person who is dangerously ill, he should not touch the garment.

הלכה ח
מִי שֶׁהָיָה לוֹ חוֹלֶה בְּתוֹךְ בֵּיתוֹ וְנִתְעַלֵּף וְסָבוּר שֶׁמֵּת וְקָרַע וְאַחַר כָּךְ מֵת. אִם בְּתוֹךְ כְּדֵי דִּבּוּר אֵינוֹ חוֹזֵר וְקוֹרֵעַ. וְאִם לְאַחַר כְּדֵי דִּבּוּר מֵת חוֹזֵר וְקוֹרֵעַ קֶרַע אַחֵר. וְכֵן מִי שֶׁאָמְרוּ לוֹ מֵת אָבִיו וְקָרַע וְאַחַר כָּךְ נִמְצָא שֶׁמֵּת בְּנוֹ. אָמְרוּ לוֹ מֵת לוֹ מֵת וְכַסָּבוּר שֶׁאָבִיו וְקָרַע וְאַחַר כָּךְ נִמְצָא בְּנוֹ. אִם תּוֹךְ כְּדֵי דִּבּוּר נוֹדַע לוֹ אֲמִתַּת הַדָּבָר יָצָא יְדֵי קְרִיעָה וְאִם לְאַחַר כְּדֵי דִּבּוּר לֹא יָצָא וְחַיָּב לִקְרוֹעַ קֶרַע אַחֵר:
כסף משנה
8.
The following rules apply when one has a dangerously ill person in his home, that person faints and he thinks that he has died and hence, he rends his garments, the sick person regains consciousness and then dies. If he dies immediately after the garments are torn, he need not rend his garments again. If he dies after even a short time has past, he must rend his garments again.
Similar concepts apply if someone tells a person that his father died and he therefore rent his garments and then it was discovered that his son died or if someone told him that a person close to him died, he thought it was his father and rent his garments and then he discovered that it was his son. If he realized the true situation immediately afterwards, he fulfilled the obligation to rend his garments. If he did not realize this until afterwards, he did not fulfill his obligation and is obligated to rend his garments again.

הלכה ט
מִי שֶׁמֵּתוּ לוֹ מֵתִים הַרְבֵּה כְּאֶחָד קוֹרֵעַ קֶרַע אֶחָד לְכֻלָּם. הָיָה בִּכְלָלָן אָבִיו אוֹ אִמּוֹ קוֹרֵעַ עַל כֻּלָּן קֶרַע אֶחָד וְעַל אָבִיו וְעַל אִמּוֹ קֶרַע אַחֵר:
כסף משנה
9.
When many close relatives die at once, a person should rend his garments once for all of them. If his father or mother are among them, he should rend his garments once for all the others, and once for his father or mother.

הלכה י
מִי שֶׁמֵּת לוֹ מֵת וְקָרַע עָלָיו וְאַחַר כָּךְ מֵת לוֹ מֵת אַחֵר. אִם בְּתוֹךְ שִׁבְעָה קוֹרֵעַ קֶרַע אַחֵר וְאִם לְאַחַר שִׁבְעָה מוֹסִיף עַל הַקֶּרַע הָרִאשׁוֹן כָּל שֶׁהוּא. מֵת לוֹ מֵת שְׁלִישִׁי אַחַר שִׁבְעָה שֶׁל שֵׁנִי מוֹסִיף כָּל שֶׁהוּא וְכֵן מוֹסִיף וְהוֹלֵךְ עַד טַבּוּרוֹ. הִגִּיעַ לְטַבּוּרוֹ מַרְחִיק שָׁלֹשׁ אֶצְבָּעוֹת וְקוֹרֵעַ. נִתְמַלֵּא מִלְּפָנָיו מַחְזִירוֹ לַאֲחוֹרָיו. נִתְמַלֵּא מִלְּמַעְלָה הוֹפְכוֹ לְמַטָּה. אָמְרוּ לוֹ מֵת אָבִיו וְקָרַע וְאַחַר שִׁבְעָה מֵת בְּנוֹ וְהוֹסִיף. מִתְאַחֶה הַתַּחְתּוֹן וְלֹא הָעֶלְיוֹן כְּמוֹ שֶׁיִּתְבָּאֵר. אָמְרוּ לוֹ מֵת בְּנוֹ וְקָרַע וְאַחַר שִׁבְעָה מֵת אָבִיו אֵינוֹ מוֹסִיף אֶלָּא קוֹרֵעַ קֶרַע אַחֵר. שֶׁאֵין אָבִיו וְאִמּוֹ בְּתוֹסֶפֶת:
כסף משנה
10.
The following rules apply when a person's close relative dies, he rends his garments because of him and then another close relative dies. If the second relative dies within the seven days of mourning, he should tear his garments again. If it is after the seven days, he need only add the slightest amount to the original tear.
If a third close relative dies after the seven days of mourning for the second, again, he need only add the slightest amount to the original tear. And he can continue in this manner until he reaches his navel. Once he reaches his navel, he should distance himself at least three thumbbreadths and rend the garment again.
When the garment is entirely torn in front, he may turn it around. When its upper portion is entirely torn, he may make the bottom the top.
If he was told: "Your father died," and he rent his garments and after the seven days of mourning, his son died and he extended the tear, he may mend the lower tear, but not the upper tear as will be explained. If he was told: "Your son died," and he rent his garments and after the seven days of mourning, his father died, he may not merely extend the tear. Instead, he must make a new tear. For extending a tear is not sufficient for his father and mother.

שופטים הלכות אבל פרק ח
Shoftim Eivel Chapter 8