To explain the above: Regarding Shabbos, the Torah states, “Keep My Shabbosos, for [Shabbos] is a sign between Me and you for your generations, so that [you] know that I, G-d, make you holy.” Rashi comments, “It is a great sign of distinction between us that I have chosen you, by granting you as an inheritance My day of rest for [your] rest,” i.e., Shabbos is an expression of G-d’s choice of the Jewish people.
Since the purpose of the mitzvah of resting on Shabbos is to serve as “a sign of distinction between us that I have chosen you,” when a Jew’s life is in danger, something is lacking in the fundamental aspect of Shabbos – the recognition of the Jews’ unique distinction. Accordingly, not only does violating the Shabbos prohibitions for the sake of pikuach nefesh fulfill the mitzvah of pikuach nefesh, but by doing so, one is carrying out a fundamental dimension of the observance of Shabbos, demonstrating the sign of distinction the Jews share with G-d.
This sign of distinction is highlighted not only by the result of the person’s act – that he saved the life of a Jew, a person whose existence makes possible the sign of Shabbos – but also the very act of violating the Shabbos prohibitions highlights the sign of distinction between a Jew and G-d: When one saves the life of a Jew who is in mortal danger on Shabbos, violating the Shabbos prohibitions to save him bolsters the sign of distinction between a Jew and G-d, demonstrating G-d’s choice of the Jewish people. It is as if the Shabbos itself demands the performance of actions that violate it – and this violation is for the sake of Shabbos – i.e., for the sake of the sign between G-d and the Jews, and every individual Jew, that Shabbos embodies.
This concept is derived from the teaching, “ ‘by fulfilling them man will live’ and not die because of them” that refers to the mitzvos as a whole, because this concept is in fact manifest in all the mitzvos. Sefer HaChinuch explains that the reason why the Shabbos prohibitions may be violated for the sake of pikuach nefesh is that “the motivating factor for the fulfillment of the mitzvos is man. Thus, by maintaining man’s existence – the motivating factor [for the mitzvos] – one is maintaining all of them.” For that reason, “all [the mitzvos] are overridden for the sake of pikuach nefesh and whoever acts energetically to violate the Shabbos [prohibitions] is praiseworthy.”
