הוו יודעין שלא כדיני ממונות דיני נפשות דיני ממונות אדם נותן ממון ומתכפר לו דיני נפשות דמו ודם זרעותיו תלויין בו עד סוף העולם שכן מצינו בקין שהרג את אחיו שנאמר (בראשית ד, י) דמי אחיך צועקים אינו אומר דם אחיך אלא דמי אחיך דמו ודם זרעותיו דבר אחר דמי אחיך שהיה דמו מושלך על העצים ועל האבנים לפיכך נברא אדם יחידי ללמדך שכל המאבד נפש אחת מישראל מעלה עליו הכתוב כאילו איבד עולם מלא וכל המקיים נפש אחת מישראל מעלה עליו הכתוב כאילו קיים עולם מלא ומפני שלום הבריות שלא יאמר אדם לחבירו אבא גדול מאביך ושלא יהו המינים אומרים הרבה רשויות בשמים ולהגיד גדולתו של הקב"ה שאדם טובע כמה מטבעות בחותם אחד כולן דומין זה לזה ומלך מלכי המלכים הקב"ה טבע כל אדם בחותמו של אדם הראשון ואין אחד מהן דומה לחבירו לפיכך כל אחד ואחד חייב לומר בשבילי נברא העולם ושמא תאמרו
The court tells them: You should know that cases of capital law are not like cases of monetary law. In cases of monetary law, a person who testifies falsely, causing money to be given to the wrong party, can give the money to the proper owner and his sin is atoned for. In cases of capital law, if one testifies falsely, the blood of the accused and the blood of his offspring that he did not merit to produce are ascribed to the witness’s testimony until eternity. The proof for this is as we found with Cain, who killed his brother, as it is stated concerning him: “The voice of your brother’s blood [demei] cries out to Me from the ground” (Genesis 4:10). The verse does not state: Your brother’s blood [dam], in the singular, but rather: “Your brother’s blood [demei],” in the plural. This serves to teach that the loss of both his brother’s blood and the blood of his brother’s offspring are ascribed to Cain. The mishna notes: Alternatively, the phrase “your brother’s blood [demei],” written in the plural, teaches that that his blood was not gathered in one place but was splattered on the trees and on the stones. The court tells the witnesses: Therefore, Adam the first man was created alone, to teach you that with regard to anyone who destroys one soul from the Jewish people, i.e., kills one Jew, the verse ascribes him blame as if he destroyed an entire world, as Adam was one person, from whom the population of an entire world came forth. And conversely, anyone who sustains one soul from the Jewish people, the verse ascribes him credit as if he sustained an entire world. The mishna cites another reason Adam the first man was created alone: And this was done due to the importance of maintaining peace among people, so that one person will not say to another: My father, i.e., progenitor, is greater than your father. And it was also so that the heretics who believe in multiple gods will not say: There are many authorities in Heaven, and each created a different person. And this serves to tell of the greatness of the Holy One, Blessed be He, as when a person stamps several coins with one seal, they are all similar to each other. But the supreme King of kings, the Holy One, Blessed be He, stamped all people with the seal of Adam the first man, as all of them are his offspring, and not one of them is similar to another. Therefore, since all humanity descends from one person, each and every person is obligated to say: The world was created for me, as one person can be the source of all humanity, and recognize the significance of his actions. The court says to the witnesses: And perhaps you will say: