Shabbos is a name of Hashem and serves as the spiritual source and sustaining force for the six days of the week — both retrospectively and prospectively.
The mitzvah of oneg Shabbos (enjoying Shabbos) is not merely supplementary but is intrinsic to the observance itself; without enjoyment, the mitzvah is incomplete.
The physical enjoyment of Shabbos (food, drink, pleasure) is necessary to allow spiritual delight to reach the Neshama, either as a conduit (Baal Shem Tov’s view) or as a transformed spiritual experience in its own right (the Maggid’s view).
Shabbos represents a dual movement — an ascent of the physical toward the spiritual and a descent of spiritual sustenance — encapsulated in the concept of אתבש and the word שבתא.
Zachor (remembering) and Shamor (keeping) of Shabbos are inseparable; one cannot truly keep Shabbos without understanding its meaning.
Shabbos is described as an אות (sign/letter) — a direct interface between humanity and Hashem, with Hashem Himself identified as the original Shabbos אות היא = הא אותי
