In Parashat Haazinu, Moshe Rabbenu foresees the time when Beneh Yisrael would betray Hashem, and he asks in bewilderment, "Ha’l’Hashem Tigmelu Zot, Am Nabal Ve’lo Hacham" – "You repay G-d this way, a foolish, unwise nation?!" (32:6). Targum Onkelos, in translating this verse, explains that Moshe here alludes to Matan Torah. How, Moshe asks, could Beneh Yisrael betray Hashem, after He brought them to Mount Sinai and gave them the Torah? We must wonder, why did Targum Onkelos mention the event of Matan Torah in this context? What is the particular relevance of Matan Torah to Moshe’s rhetorical question about Beneh Yisrael’s disobedience? The answer, surprisingly, has to do with the unique importance of Shabbat. The Gemara teaches that if a person observes Shabbat, then even if he had worshipped idols, his sins are forgiven. The Taz (Rav David Segal, 1586-1667) interprets this to mean that even if a sinner repented for his wrongdoing, he does not achieve atonement until he observes Shabbat. There is something special about Shabbat observance that is necessary for earning atonement. The commentators explain this concept based on the Zohar’s remark that a Jew becomes purified by gathering together with his fellow Jews. When a large number of Jews assemble, this has a special "purifying" effect upon their souls. This can be understood by way of an analogy to a magnet. A small magnet will not be drawn to another magnet unless it is very close. However, if a magnet is very large, then the magnetic pull is much stronger, and the magnet is attracted to another magnet even from a distance. Similarly, the Jewish soul has a portion in the heavens and a portion here on earth. When a person sins, he disconnects his heavenly soul from his earthly soul. Given the vast distance between heaven and earth, it is not easy to reconnect one’s earthly soul to his soul in the heavens. This can be accomplished only when we join together in prayer and learning. Such an assembly creates a strong spiritual force, like the force of a large magnet, which allows us to reconnect to our heavenly souls, thereby fully repairing the damage we caused as a result of our sins. This is why the Shabbat experience is such a vital part of Teshuba. During the week, we are preoccupied with our careers and businesses and have little time for assembling in the synagogue. Shabbat is the day when we have more time for meaningful prayer and study, and this is, indeed, one of the most important purposes of Shabbat. This is when we come together to be "purified," to reconnect with our pure, heavenly souls, and for this reason, Shabbat is critical for earning complete atonement and forgiveness. With this background, we can return to our verse in Parashat Haazinu. Moshe asks, "Ha’l’Hashem Tigmelu Zot," which can be read to mean, "Are you giving G-d only ‘Zot’?" The word "Zot" in Gematria equals 408 – the sum of the Gematria of the three words, "Som" (fasting), "Kol" (the sound of prayer) and "Mammon" (money given to charity). These are the three familiar components of repentance, and each of these words in Gematria equals 136, for a total of 408. Moshe Rabbenu here is teaching us that these three are all necessary, but insufficient. We cannot earn forgiveness only through fasting, prayer and charity. We also need to properly experience Shabbat by joining together with our fellow Jews in the synagogue. This is why Targum Onkelos mentions the event of Matan Torah in this context. G-d was going to give the Torah on Friday, but Moshe added a day of preparation so that the Torah would be given specifically on Shabbat. He wanted to establish the precedent of Jews assembling to study Torah on Shabbat – just as our ancestors assembled at Mount Sinai on Shabbat to receive the Torah. Coming together with our fellow Jews is an indispensable part of our Teshuba process – in addition to fasting, prayer and charity. We must never underestimate the importance of joining together with other Jews for prayer and study, particularly on Shabbat, the day especially designated for this purpose. Let us come together, learn from one another, help one another, and experience the beauty of Torah and Tefila together, so we can all grow together and reach the great spiritual heights that can be reached only as a large, unified group.