Vayelech opens with Moses walking through the Jewish camp on the final day of his life to say goodbye to his beloved people. He teaches them the mitzvah of Hakel, the once-in-seven-years gathering of the entire nation to hear the king read certain passages from the Torah. G-d commands that a special Torah, written by Moses, be placed by the Levites at the side of the Holy Ark to bear witness against Israel if they were to ever deviate from its teachings.
The Shabbos between Rosh Hashanah and Yom Kippur is called Shabbos Shuvah, Shabbos of Return because its special haftarah reading begins with the words Shuvah Yisrael “Return O Israel,” from the prophecy of Hoshea. It is also referred to as Shabbos Teshuvah because it falls during the Ten Days of Repentance. The prayer service on this Shabbos is the same as on an ordinary Shabbos with the exception of the additions that are made to the Amidah throughout the Ten Days of Repentance. Avinu Malkenu is not recited. In the blessing at the end of the Magen Avot prayer following evening services on Friday night, the words ha-Melech ha-Kadosh are substituted for ha-El ha-Kadosh. It is customary for the rabbi to expound on matters related to teshuvah.