Rav Ami said: There is no death without sin; were a person not to sin, they would not die. And there is no suffering without iniquity.
(יז) וּמֵעֵ֗ץ הַדַּ֙עַת֙ ט֣וֹב וָרָ֔ע לֹ֥א תֹאכַ֖ל מִמֶּ֑נּוּ כִּ֗י בְּי֛וֹם אֲכָלְךָ֥ מִמֶּ֖נּוּ מ֥וֹת תָּמֽוּת׃
(17) but as for the tree of knowledge of good and bad, you must not eat of it; for as soon as you eat of it, you shall die.”
Rabbi Matya ben Ḥarash asked Rabbi Elazar ben Azarya when Rabbi Elazar was in Rome: Have you heard the teaching that there are four distinctions in the process of atonement that Rabbi Yishmael would derive? He said to him: They are not four but three distinctions, and repentance is necessary with each one. These are the categories:
If one violates a positive mitzva and repents, he is forgiven even before he moves from his place, i.e. immediately, as it is stated: “Return, you backsliding children, I will heal your backsliding” (Jeremiah 3:22), implying that when one repents he is immediately forgiven.
If one violates a prohibition and repents, repentance suspends his punishment and Yom Kippur atones for his sin, as it is stated: “For on this day shall atonement be made for you, to purify you from all your sins” (Leviticus 16:30).
If one commits a transgression that warrants karet or a sin punishable by death from the earthly court and then repents, repentance and Yom Kippur suspend his punishment, and suffering absolves and completes the atonement, as it is stated: “Then will I visit their transgression with the rod, and their iniquity with strokes” (Psalms 89:33).
But in the case of one who has caused desecration of God’s name, his repentance has no power to suspend punishment, nor does Yom Kippur have power to atone for his sin, nor does suffering alone have power to absolve him. Rather, all these suspend punishment, and death absolves him, as it is stated: “And the Lord of Hosts revealed Himself to my ears: This iniquity shall not be atoned for until you die” (Isaiah 22:14).
(ה) וְאַ֨ךְ אֶת־דִּמְכֶ֤ם לְנַפְשֹֽׁתֵיכֶם֙ אֶדְרֹ֔שׁ מִיַּ֥ד כָּל־חַיָּ֖ה אֶדְרְשֶׁ֑נּוּ וּמִיַּ֣ד הָֽאָדָ֗ם מִיַּד֙ אִ֣ישׁ אָחִ֔יו אֶדְרֹ֖שׁ אֶת־נֶ֥פֶשׁ הָֽאָדָֽם׃ (ו) שֹׁפֵךְ֙ דַּ֣ם הָֽאָדָ֔ם בָּֽאָדָ֖ם דָּמ֣וֹ יִשָּׁפֵ֑ךְ כִּ֚י בְּצֶ֣לֶם אֱלֹהִ֔ים עָשָׂ֖ה אֶת־הָאָדָֽם׃
(5) But for your own life-blood I will require a reckoning: I will require it of every beast; of man, too, will I require a reckoning for human life, of every man for that of his fellow man! (6) Whoever sheds the blood of man, by man shall his blood be shed; for in the Divine Image did God make man.
From where is it derived that with regard to those executed by sword, e.g., murderers, their execution is administered from the neck, and nowhere else? The verse states: “And so shall you put away the innocent blood from your midst” (Deuteronomy 21:9), likening all spillers of blood to the beheaded calf brought for an unresolved murder. Just as there, the calf is beheaded from the neck, so too, murderers are beheaded from the neck. The Gemara asks: If so, just as there, in the case of the beheaded calf, it is beheaded with a cleaver [kofitz] and at the nape of the neck, here too the court executes murderers with a cleaver and at the nape of the neck. Rav Naḥman said that Rabba bar Avuh said that the verse says: “And you shall love your neighbor as yourself” (Leviticus 19:18), from which it is derived: Choose for him an agreeable death. It is prohibited to abuse a guilty person while executing him, and chopping off his head with a cleaver is an unseemly death. The murderer is beheaded from the neck, not with a cleaver, and not by the other methods employed in beheading the calf.
(ה) כֵּיצַד מְאַיְּמִין אֶת הָעֵדִים עַל עֵדֵי נְפָשׁוֹת, הָיוּ מַכְנִיסִין אוֹתָן וּמְאַיְּמִין עֲלֵיהֶן. שֶׁמָּא תֹאמְרוּ מֵאֹמֶד, וּמִשְּׁמוּעָה, עֵד מִפִּי עֵד וּמִפִּי אָדָם נֶאֱמָן שָׁמַעְנוּ, אוֹ שֶׁמָּא אִי אַתֶּם יוֹדְעִין שֶׁסּוֹפֵנוּ לִבְדֹּק אֶתְכֶם בִּדְרִישָׁה וּבַחֲקִירָה. הֱווּ יוֹדְעִין שֶׁלֹּא כְדִינֵי מָמוֹנוֹת דִּינֵי נְפָשׁוֹת. דִּינֵי מָמוֹנוֹת, אָדָם נוֹתֵן מָמוֹן וּמִתְכַּפֵּר לוֹ. דִּינֵי נְפָשׁוֹת, דָּמוֹ וְדַם זַרְעִיּוֹתָיו תְּלוּיִין בּוֹ עַד סוֹף הָעוֹלָם, שֶׁכֵּן מָצִינוּ בְקַיִן שֶׁהָרַג אֶת אָחִיו, שֶׁנֶּאֱמַר (בראשית ד) דְּמֵי אָחִיךָ צֹעֲקִים, אֵינוֹ אוֹמֵר דַּם אָחִיךָ אֶלָּא דְּמֵי אָחִיךָ, דָּמוֹ וְדַם זַרְעִיּוֹתָיו. דָּבָר אַחֵר, דְּמֵי אָחִיךָ, שֶׁהָיָה דָמוֹ מֻשְׁלָךְ עַל הָעֵצִים וְעַל הָאֲבָנִים. לְפִיכָךְ נִבְרָא אָדָם יְחִידִי, לְלַמֶּדְךָ, שֶׁכָּל הַמְאַבֵּד נֶפֶשׁ אַחַת מִיִּשְׂרָאֵל, מַעֲלֶה עָלָיו הַכָּתוּב כְּאִלּוּ אִבֵּד עוֹלָם מָלֵא. וְכָל הַמְקַיֵּם נֶפֶשׁ אַחַת מִיִּשְׂרָאֵל, מַעֲלֶה עָלָיו הַכָּתוּב כְּאִלּוּ קִיֵּם עוֹלָם מָלֵא. וּמִפְּנֵי שְׁלוֹם הַבְּרִיּוֹת, שֶׁלֹּא יֹאמַר אָדָם לַחֲבֵרוֹ אַבָּא גָדוֹל מֵאָבִיךָ. וְשֶׁלֹּא יְהוּ מִינִין אוֹמְרִים, הַרְבֵּה רָשֻׁיּוֹת בַּשָּׁמָיִם. וּלְהַגִּיד גְּדֻלָּתוֹ שֶׁל הַקָּדוֹשׁ בָּרוּךְ הוּא, שֶׁאָדָם טוֹבֵעַ כַּמָּה מַטְבְּעוֹת בְּחוֹתָם אֶחָד וְכֻלָּן דּוֹמִין זֶה לָזֶה, וּמֶלֶךְ מַלְכֵי הַמְּלָכִים הַקָּדוֹשׁ בָּרוּךְ הוּא טָבַע כָּל אָדָם בְּחוֹתָמוֹ שֶׁל אָדָם הָרִאשׁוֹן וְאֵין אֶחָד מֵהֶן דּוֹמֶה לַחֲבֵרוֹ. לְפִיכָךְ כָּל אֶחָד וְאֶחָד חַיָּב לוֹמַר, בִּשְׁבִילִי נִבְרָא הָעוֹלָם. וְשֶׁמָּא תֹאמְרוּ מַה לָּנוּ וְלַצָּרָה הַזֹּאת, וַהֲלֹא כְבָר נֶאֱמַר (ויקרא ה) וְהוּא עֵד אוֹ רָאָה אוֹ יָדָע אִם לוֹא יַגִּיד וְגוֹ'. וְשֶׁמָּא תֹאמְרוּ מַה לָּנוּ לָחוּב בְּדָמוֹ שֶׁל זֶה, וַהֲלֹא כְבָר נֶאֱמַר (משלי יא) וּבַאֲבֹד רְשָׁעִים רִנָּה:
...Therefore but a single person was created in the world, to teach that if any man has caused a single life to perish from Israel, he is deemed by Scripture as if he had caused a whole world to perish; and anyone who saves a single soul from Israel, he is deemed by Scripture as if he had saved a whole world.
A Sanhedrin that executes a transgressor once in seven years is characterized as a destructive tribunal. Since the Sanhedrin would subject the testimony to exacting scrutiny, it was extremely rare for a defendant to be executed. Rabbi Elazar ben Azarya says: This categorization applies to a Sanhedrin that executes a transgressor once in seventy years. Rabbi Tarfon and Rabbi Akiva say: If we had been members of the Sanhedrin, we would have conducted trials in a manner whereby no person would have ever been executed. Rabban Shimon ben Gamliel says: In adopting that approach, they too would increase the number of murderers among the Jewish people. The death penalty would lose its deterrent value, as all potential murderers would know that no one is ever executed.