Nestled within Torat Kohanim, Sefer VaYikra, is a short Parashah that contains laws relating to the rest of Bnei Yisrael. Parashat Kedoshim opens with the general requirement for Bnei Yisrael to be “Kedoshim” (the definition of this word is hotly debated amongst the Meforshim) and then lists various Mitzvot, which presumably are ways to achieve this status. The majority of these Mitzvot are new ones, not found anywhere previously in the Torah, but the prohibition of “Lo Tignovu,” “Do not steal” (VaYikra 19:11) seems identical to a similarly worded Mitzvah found in the Aseret HaDibrot, “Lo Tignov” (Shemot 20:13). The Gemara (Sanhedrin 86a) explains that there is a difference between the two Mitzvot: the prohibition found in the Aseret HaDibrot, in the context of capital crimes, is itself a capital crime, kidnapping; in Parashat Kedoshim, on the other hand, the prohibition is against stealing mere money.
While this answer clarifies that the Torah did not truly repeat itself, it does not explain why the Torah included this Mitzvah specifically in the context of Parashat Kedoshim. Rashi explains the immediate context of the Isur in the Pesukim, “Lo Tignovu VeLo Techachashu VeLo Teshakeru … VeLo Tishave’u ViShmi LaShaker,” “Do not steal, and do not deny, and do not lie…and do not falsely swear by My name” (VaYikra 19:11-12). Rashi (s.v. Lo Tignovu VeLo Techachashu…, quoting Torat Kohanim 2:5) explains that this Pasuk is organized successively: if one steals, then he will deny it, then he will lie to others about it, and he will ultimately swear falsely in court, leading to the conclusion, “VeChilalta Et Sheim Elokecha,” “And you will desecrate the name of your God” (19:12).
This explanation of Semichut as successive is uncommon in Rashi’s commentary. One of the few other locations where Rashi talks about successive acts is in the beginning of Parashat Ki Teitzei. There, the successiveness is not in only two Pesukim but in three seemingly unrelated topics, each discussed in some detail. The opening topic is that of the Eishet Yefat To’ar, a non-Jewish woman whom a Jewish soldier sees and lusts for during battle; the Torah then goes on to explain that the soldier is allowed to marry this girl through a process in which she is supposed to become extremely unattractive, hopefully diverting the soldier from a solely lustful marriage. The Torah then describes the rules regarding an Ishah Senu’ah, a wife whom her husband loves less than his other wife; the law is that the man’s oldest son must be treated as the Bechor, with his appropriate double inheritance, regardless of his father’s love for his mother. The final topic is the Bein Soreir UMoreh, the rebellious son who is killed by Beit Din, seemingly as a preemptive measure. These topics show a more obvious succession, as Rashi (Devarim 21:11 s.v. VeLakachta Lecha Ishah, quoting Tanchuma 1) articulates: this is actually a warning to the soldier. The Parashah of Eishet Yefat To’ar is merely a loophole for the soldier not to give into his Yeitzer HaRa by violating an Aveirah because of his lust. Still, the marriage is not optimal; that is why many steps are taken to make the woman unattractive to the man. But if the marriage does go through, the Torah warns, the consequences will most likely be bad. The captured woman will generally become an Ishah Senu’ah, and then she will give birth to a son hated like she was. The son, therefore, will respond, becoming a Bein Soreir UMoreh.
There is a slight connection between these two distinct successions. A technical connection is that each contains an element of stealing. In Parashat Kedoshim, the entire process begins when someone steals money. In Parashat Ki Teitzei, stealing is the near end of the process: a Bein Soreir UMoreh is killed only after he steals meat and wine from his parents. However, the connection transcends this detail. Mitzvot are never about only the letter of the Torah’s law; the spirit is just as important. In fact, Ramban explains the commandment of “Kedoshim Tihyu” as a prohibition against being a Naval BiRshut HaTorah, one who is legally within the bounds of Halachah but is clearly in violation of the Torah’s intent. Even one who does not violate Halachah but disregards its intent can damage himself to the point that he is no longer Kadosh. “Lo Tignovu” shows a similar type of damage: one who commits a petty crime, such as stealing money, will ultimately be Mechaleil Sheim Hashem, the exact opposite of being Kadosh. Similarly, in general, a person should never marry just out of lust. The Torah’s acceptance of an Eishet Yefat To’ar is merely a concession to the reality that the Yeitzer HaRa is too strong in a war, in which emotions run high. Still, the intent of the Torah is for a man not to marry such a woman, and as Rashi explains, the Torah predicts the results to be disastrous for the entire family.
This can, perhaps, shed light upon what it means to be Kadosh. The Torah implies in its Halachot that even relatively minor Isurim are to be taken seriously and kept strictly. Even a concession of the Torah should be avoided, though it is not technically against the law. As Ramban states, even if one is acting completely within the boundaries of Halachah, it is still problematic to be a Naval. If one is truly to be close to Hashem, as the Kohanim are, then he should try his hardest to listen not only to the letter of the law, not even just to the spirit of the law, but to the true guidelines of right and wrong. Hashem, of course, is always right; if we are to be Kedoshim like He, then we must be as well.