“It shall be a sign for all time between Me and the people of Yisrael. For in six days Hashem made heaven and earth, and on the seventh day He ceased from work and was refreshed” EXODUS 31:17 (The Israel Bible™)
The Shabbat (שבת), ‘Sabbath,’ is designated as a sign between Hashem and the Children of Israel that Hashem created the world, and resting from work on Shabbat is the sign that the Jewish Nation recognizes God as the Creator. Each week, Jews reaffirm their submission to Hashem by sanctifying the Shabbat, and they recite this verse during the Shabbat prayers. Though the observance of Shabbat was commanded to the Children of Israel, the message of Shabbat, that God created the universe and everything in it, is a universal one.