Now the heavens and the earth were completed and all their host. And G-d completed on the seventh day His work that He did, and He abstained on the seventh day from all His work that He did. And G-d blessed the seventh day and He sanctified it, for on it He abstained from all His work that G-d created to do. (Breishis 2:1-3)

The Kuzari asks a question that is so obvious that when you hear it you will wonder why you had never thought of it. To appreciate the power of the question let us back up and establish some facts, a few givens. We can know the length of a day and easily measure it by the motion of the sun. The sun is a reliable clock in concert with the earth spinning at a thousand miles an hour counting out twenty-four hours. The moon dances across the sky like the blink of an eye, opening fully and closing to a squint in the course of 29 and ½ days. It is our heavenly calendar.

A solar year can easily be observed by the winter solstice and the summer equinox. At certain times in the year the sun reaches a point in the horizon where the pendulum begins to return in the other direction. When the same moment of zenith arrives then we have effectively completed a 365 and ¼ day elliptical journey around the sun at a steady speed of approximately 67,000 miles per hour.

Now we are almost ready for the big question. Shabbos is a sacred appointment for Jews around the world for thousands of years now. We take that time very seriously and therefore it is mysteriously understandable why it sacred and we keep track of the steady rhythm of a week. Why in the world do disparate and disconnected cultures around the world conform to a seven-day week. Where in the heavenly bodies is there any celestial sign of a seven-day period?

The answer is simple and obvious. We can go back to the very beginning of creation, “And G-d blessed the seventh day and He sanctified it”. Before the existence of the Jewish Nation there has been a Holy Shabbos waiting for a people to appreciate its specialness. The whole world was aware of the notion that the world had been created and completed in seven days. It was common knowledge to all of mankind.

Similarly, we find that there are more than 500 variant versions of flood story spanning every continent, culture and language. Why should that be true even for those peoples not in the loop of biblical tradition? The answer is that it is a given, a fact of history that predated the giving of the Torah and it has been preserved as a part of cultural consciousness generation after generation ever since. Like a giant stone that crashes into a body of water it sends out waves and ripples that continue till today.

So too Shabbos is a fact of creation that has been preserved in the collective memories of all peoples for all time. Even if they can’t identify the source, we know what it is and that source, our sages tell us is the source of blessing and the Jewish People have come to know it and keep it holy.

Now consider that a billion and a half adherents to the ways of Ishmael keep Friday as their day of rest but they absolutely agree that Shabbos is the next day. There are a billion and half followers of Essav – Edom resting on Sunday and happy to admit that the day before is actually Shabbos, while the rest of the world remains loyally fixed to a seven-day week. The Torah boldly claims, “And the Children of Israel keep the Shabbos, to make the Shabbos for their generations a covenant for eternity. Between Me and the Children of Israel it is an eternal sign that HASHEM made the heavens and the earth and on the seventh day He rested and was refreshed. (Shemos 31:16-17) That day cannot get lost in the count!

It has been said that more than the Jews have kept the Shabbos, the Shabbos has kept the Jews. I would like to add one caveat. More than the Jews have kept the Shabbos Holy, the Shabbos has kept the Jews Holy. Can you have a bigger sign than that?!