Nitzavim: Entering the Covenant of Unity and Yichud Hashem

Rabbi Zweig addresses several fundamental questions in Parshas Nitzavim. First, the Ramban (רמב"ן) learns that "lo bashamayim hi" refers to teshuvah, whereas the Gemara (גמרא) clearly applies this phrase to Torah (תורה). Second, how can future generations become obligated by a covenant they never made? The Maharal answers that a later Beis Din cannot overturn an earlier ruling, but this only explains legal obligation — how does it create a personal oath (shevuah) for those not present? Third, the parsha introduces the covenant of Arvot Moav, establishing "kol Yisrael areivim zeh bazeh" (all Israel are guarantors for one another), yet Parshas Bechukosai already taught "v'chashlu ish ba'avon achiv" (mutual responsibility for sin). What new dimension does Arvot Moav add? Fourth, why does Ezra's takanah require reading the Bechukosai curses before Shavuos (written in plural form) and the Ki Savo curses before Rosh Hashanah (written in singular form)? The Rambam (רמב"ם) in Hilchos Krias Shema records that Yaakov Avinu, before his death, gathered his sons and asked if anyone among them rejected yichud Hashem (ה׳) (the unity of God). When the divine presence departed and he could not reveal the time of redemption, he suspected a flaw in their commitment to God's unity. The Gemara's proof-text seems odd: why would inability to reveal the ultimate redemption specifically indicate doubt about yichud Hashem rather than some other sin? The answer reveals two fundamentally different types of unity. One can assemble a group of mercenaries, each working for personal gain but cooperating because mutual assistance increases individual success. Alternatively, a leader can inspire people to share a common vision — everyone commits to the same goal, such as establishing a new nation. In the first model, each person works for himself while recognizing the utility of teamwork. In the second, individuals genuinely unite around a shared purpose.