Once upon a time the Emperor asked Rabbi Joshua, the son of Hananiah, "Dear friend, tell me, why does Sabbath food taste so pleasant and so much better than the food you prepare during the week?"

Rabbi Joshua replied, "My Lord Emperor, I will tell you the truth. We have a root called Sabbath which we put into our food and which makes it taste so pleasant." Then, the Emperor said, "Friend, give me some of that root; I will put it into my food so that it may also have a good taste."

Then Rabbi Joshua answered and said, "Lord Emperor, even if I were to give it to you it would not help you, for only he who observes the Sabbath can taste the root. For him who does not observe the Sabbath the root is tasteless. Therefore, Lord Emperor, I cannot give it to you."

And so he put him off in regard to the Sabbath.