(Exodus 16:28) "And the L–rd said to Moses: How long will you refuse to keep, etc.": R. Yehoshua says: The Holy One Blessed be He said to Moses: Moses, say to Israel: I took you out of Egypt and I split the sea for you, and I brought down the manna for you, and I brought up the well, and I swept in the quail for you, and I fought the war with Amalek for you, and I wrought miracles and mighty acts for you—"How long will you refuse to keep My mitzvot (commandments)h and My laws?" Lest you say that I have imposed too many mitzvoth upon you, this Sabbath (alone) did I charge you with at Marah to keep it, and you have not kept it! Lest you say: What reward is received by the keeper of the Sabbath? It is written (Isaiah 56:2) "Happy is the man who does this, and the son of man who holds fast to it—who keeps Sabbath not to profane it—He keeps his hand from doing all evil." We are hereby apprised that one who keeps the Sabbath is kept far from transgression.