The two forms of holiness – Shabbat and festivals – are different. Shabbat represents creation. The festivals represent redemption. Shabbat is about the presence of God in nature. The festivals are about the presence of God in history. Accordingly, Shabbat was declared holy by God himself at the culmination of creation. God "blessed the seventh day and made it holy" (Gen 2:3). The festivals, by contrast, are sanctified by the Jewish people through their determination of the calendar—just as redemption takes place in history when we act in partnership with God. Thus, on Shabbat, we end the Kiddush by saying  mikadesh hashabbat  meaning that it is God who sanctifies Shabbat; but on festivals, we say  mikadesh yisrael v'hazmanim, meaning, "God sanctifies Israel, and Israel in turn sanctifies time." Shabbat is holiness from above to below, and the festivals are holiness from below to above.


haggadah Section: Kadesh
Source: Koren Haggadah p. 14