“For this mitzvah is not far from you; it is not in heaven that you shall say ‘Who will ascend for us to the heavens…’” (Deuteronomy 30:11) Nachmanides states in his commentary that this verse refers to the positive commandment of repentance. He cites two other verses as sources for this mitzvah: “…you shall return to the L-rd your G-d…”, (Ibid. 4:30) and, “And you shall return to your heart…”. (Ibid. 30:1) He writes that the Torah’s use of verbs that can be understood as either future tense or as imperatives indicates that teshuvah is both a promise for the future and a positive commandment as well.
Rabbeinu Yonah of Gerona writes at the beginning of Gates of Repentance (Shaarei Teshuvah, Shaar 1:1) “We have been exhorted to repent by the Torah in a number of places.” He clearly implies that aside from the tremendous kindness that G-d has shown us in giving us the opportunity to repent, He has also commanded us to repent.
The language of Maimonides (Laws of Repentance 1:1) suggests that he does not consider teshuvah to be an independent mitzvah. “All the commandments in the Torah…. if a person transgressed one of them, whether intentionally or unintentionally, when he repents and returns from his sin, he is obligated to confess in front of the L-rd, Blessed is He.” It would seem that the mitzvah here is confession at the time of repentance, but not repentance in and of itself. He also does not list repentance as a mitzvah in his Book of the Commandments; in Mitzvah 73 he lists only “confession” as a mitzvah. (Minchat Chinuch, Mitzvah 364)
Rabbi Meir Simchah Hacohen (Meshech Chochmah, Deuteronomy 31:17) offers a rationale for the Rambam’s position. He says that the fact that a person has transgressed does not diminish his obligation to desist from sin or to fulfill mitzvot. In the words of the Meshech Chochmah, “The first prohibition that prevented him from sin before he sinned, prevents him from sinning also after he has sinned.” Hence the sinner’s obligation to rectify his ways is really intrinsic to every mitzvah. What does the process of “teshuvah” require of the “baal teshuvah” that is not required of him by the mitzvah that he transgressed?
Rabbi Meir Simchah answers that even if one has ceased sinning and has indeed mended his ways the Torah requires that he confess his sin before G-d. His resolve never to return to the sin for which he is repenting is part of the attitude necessary for sincere confession of his sin. Thus, that which is unique to this mitzvah is only the obligation to confess, and therefore Maimonides counts “confession” as a mitzvah but not “teshuvah”.
He adds that the process of teshuvah can sometimes impose an obligation upon the returnee beyond abandoning sin and beyond confession. A person who has sinned may be obligated to cure himself by going to the opposite extreme in the area in which he sinned. According to Rabbi Meir Simchah part of the repentance process is the obligation to react to sin by striving to reach its “opposite pole”; this temporary “extremism” will achieve the ideal of the “middle path” without fear of stumbling in sin again.
Maimonides heading for the Laws of Repentance reads, “One positive commandment, and that is, that a sinner shall repent his sin before G-d and confess.” The Kiryat Sefer (Hilchot Teshuvah, Ch.1) maintains that confession and repentance are two equally obligatory aspects of one mitzvah. Repentanc, which involves regret for past sins and resolve not to repeat them, is the start of the process of purification; sincere confession of sin is the conclusion of the process and is analogous to immersion in a mikveh (ritual bath).
Rabbi Josef Dov Soloveitchik (On Repentance Pp. 78-80) explains the concept of repentance based on a tradition from his great-grandfather. According to the tradition, Maimonides understands that repentance is indeed a mitzvah, as is strongly implied by the many verses in the Torah commanding the Jewish people to repent. In the words of Rabbi Soloveitchik “But do we really need evidence of this sort? Can one really contemplate the possibility that confession be considered a precept while repentance is not? What would be the significance of confession without repentance?”
Rabbi Soloveitchik explains that there are two parts to the process of repentance; the action required by the mitzvah, which is confession, and the fulfillment of the mitzvah which is the subsequent change, that we call teshuvah. Maimonides only counts as a mitzvah the action that is required even though he maintains that the resultant teshuvah is an essential aspect of the mitzvah.