אחד ושמו אחד 'ד – Hashem Echad u’Shemo Echad. Hashem is one; and His Name is One.
When we think about it, Shabbos is the only perfect day of the Seven Days of Creation. Every day required added creations to come into play on that specific day. Shabbos is the only day that achieved perfection just by virtue of it having been created. Hashem did not do anything extra – but rest. The day was complete, shleimus, perfection. Thus, when we properly observe both the prohibitive and positive aspects of Shabbos – zachor v’shamor, remember and guard, [These two were uttered as one word, fusing together the positive and negative into one perfection. We connect to Hashem’s unity.] What an unprecedented opportunity is availed us on Shabbos: to tap into perfection – not just any sort of perfection – but perfection personified by Hashem.
