Rabbi Aharon Soloveichik explained that this midrash does not refer to Kayin's intent in his act of murder. Rather, it describes the implications of Kayin's response to God's words of rebuke for this act. There is, in fact, a difference of opinion in the midrash whether or not Kayin's words constituted an expression of repentance, and this controversy is reflected in the way the major commentators translate his words. According to Rashi, Kayin said," is my sin too great to bear?" meaning that he did not recognize the gravity of his sin, and, consequently, did not repent. According to the Ramban, however, he said, "my sin is too great to bear," and did actually confess and repent for his sin. Nechama Leibovitz once pointed out that Rashi's approach seems to fit more closely into the plain meaning of the verses, which present Kayin as the sole aggressor in the episode.
Rabbi Soloveichik understood Kayin's words in a different way from both Rashi and Ramban. He explained Kayin to be saying that his crime was so great that he was not able to repent. That attitude, Rabbi Soloveichek said, is the greatest crime of all, because it denies the ability of free choice, and reduces man to a cog in machine .It was in this sense, he continued, that the rabbis said that Kayin wished to return the world to its primitive state of tohu and bohu.
I believe that Rabbi Soloveichik's explanation of the midrash can be expanded upon based on another midrash that we cited, in our last message. The midrash says that God created worlds and destroyed them until He finally created the world that we now live in. Although Rabbi Menachem Kasher, in his Torah Shleimah, takes this midrsah figuratively, others take it in a literal sense, as elaborated upon by Rabbi Yisroel Lifshitz in his essay Ohr HaChaim. Why did God create and destroy these worlds? Last week we explained this midrash in a way that connects it to Moshe's shattering of the tablets. However, the chassidic commentary Noam Elimelech explains it differently. He says that this midrash is explaining how there can be such a thing as repentance. After all, after an act is done, the effects are there. Yet, through sincere repentance, one receives forgiveness and atonement, as if the action was never done. It was this ability, Rabbi Elimelech explained, that God implanted in the world through creating worlds and destroying them until He finally arriving at the world we now inhabit. This is also the meaning of the Talmudic statement that repentance is one of the seven things that preceded the creation of the world. As the Maharal of Prague explains, the world could not exist without the capacity for repentance, and, so, God created that capacity before the world we live in was created.
Rav Avraham Yitzchak Kook, in his Oros HaTeshuvah, writes that repentance is really a universal process, a process of the entire universe gradually returning to its divine source. As we move towards the historical fulfillment of the Biblical prophecies, the world itself is moving as well. Without this capacity for return, the world would truly be in a state of chaos, of tohu and bohu. When Kayin told God that he did not have the capacity to repent, he was, in effect, expressing his desire to reduce the world to its former chaotic state, void of meaning. Instead of utilizing the capacity for change that God implanted in the universe, he denied that capacity, and tried to bring the world down to his level. This was, indeed, his greatest crime.