Pop singer Madonna came this week to Tel Aviv to take part in a congress of Kabbala studies. According to press releases, she is going to stay in Israel until Sunday night and will have on the last day of her visit, the opportunity to visit the graves of Jewish Tzaddikim (righteous holy people) near Safed, a small town in northern Israel.

Why Safed? What does Kabbala mean? (Literally it means "Receiving" in Hebrew).

I am not so sure the press has given the correct answers to these and other questions related to the background of this visit. Here is my humble contribution.

Safed , one of the four "holy cities" in Israel, together with Jerusalem, Hebron and Tiberias, is actually a small mountain town (27,000 residents). As opposed to other historical cities in Israel, it is not even mentioned in the Bible.

Its golden era was during the Middle Ages, when it functioned as a Crusaders fortress and a Moslem administrative centre. But it was only in the 16th century that Safed was a city of international importance, as well as a Jewish cultural Capital.

What made Safed so special is linked to what Maddona is looking in Israel for.

The Jewish congregation of Safed is the oldest in Israel. It has been there for the last 800 years. But during the Crusaders time it was very small, because the Christian knights did everything they could to massacre Jews (and Moslems).

The turning point was the conquest of the area by the Turkish Sultanate. This Moslem empire gave shelter to the Spanish Jews during their mass expulsion in the end of the 15th century. The Turks, who were great warriors and administrators, did not master commerce, industry and science. They understood the great potential of Spanish Jews who were experts in these fields, and gave them asylum.

Some of those Jews, a few thousands, came to Safed and settled down there. Safed attracted them for two main reasons: The good water sources and the closeness to the grave site of the founder of the Kabbala, the Jewish mysticism, Rabbi Shimon Bar Yochai.

The water was needed for establishing a wool manufacturing centre which became one of the biggest in the world, and made Safed a flourishing city. The grave of Bar yochai, and an ancient tradition according to which the Messiah will first come out Safed, attracted some of the greatest Jewish religious scholars of Spain, most of them Kabbalists.

In Safed of the 16th century settled down Rabbi Yosef Karo, of Toledo, the greatest Jewish Law expert of the new era, who wrote the codification book "Shulkhan Arukh", the third most important Jewish book, after the Bible and the Talmud.

Another great Kabbalist was Shlomo Alkabetz, who is known today more for his religious poetry. His most famous liturgical poem is called "Lecha Dodi". It is used in every Synagogue to receive Sabbath. His brother in law was Rabbi Moshe Kordoveiro, a student of Rabbi Karo, who wrote the first book which explains the Kabbala methodically.

The greatest student or Rabbi Kordoveiro was Rabbi Yizhak Luria, who is more known as HaAri Hakadosh. Luria Died when he was only 38 years old. Only two and a half years he spent in Safed. But it was in that short period of time that he created a Kabbalist theoretical movement that has had an immense influence on the life of almost every Jew since then.

What does Kabbala mean? If you have time and patience just go to a site called http://kabbalaonline.org/ and start reading. It will take you a few days. Otherwise, here is a somewhat simplified explanation.

According to the Talmud, the world of Torah (the knowledge of Judaism) is based on four layers: Pshat (Literal meaning, in Hebrew), Remez (Implication), Drash (Interpretation) and Sod (Secrecy). Every one of these layers is a different way of weighing the same words of the Torah. The deepest layer is the Secrecy. The Secrecy doctrine, which includes the Kabbala, is so mysterious, deep, and special, that not everyone can understand it. Therefore, it is recommended by Jewish scholars to start studying it only at the age of 40. A younger person does not have the spiritual maturity needed to cope with its depths.

The Secrecy doctrine exists since the 2nd century, but did not appear in any book until the end of the 14th century, when a Spanish Jewish scholar named Rabbi Moshe de Leon rewrote and edited it in a book called "Seffer Hazohar" (The book of Glow, in Hebrew). The contents of the book is attributed to the Rabbi Shimon Bar Yochai (mentioned above) who had lived 1300 years before the time of de Leon. Believers claim that Bar Yochai wrote the book, but Kabbala researchers say that the text was written much later, in the middle ages.

"Seffer Hazohar" is not a text book. It is a collection of ideas and Torah material. Only in the end of the 15th century, another Spanish Rabbi, Moshe Cordoveiro, who later moved to Safed, wrote structured lessons which enabled a systematic studying of Kabbala.

As opposed to the other three layers of Torah world, dealing primarily with the Jewish religious laws, the Secrecy doctrine deals with the philosophical side of Judaism: For example, the eternal question of "Why do righteous people suffer in our world, and why are wicked people so successful?"

The Kabbala, developed in Safed by a genius nicknamed "HaAri Hakadosh" in the 16th century, uses abstract concepts which are incomprehensible to outsiders: "Elohut" (Divinity) and "Tzimtzum" (Reduction), for instance. The Divinity filled in the past the whole universe. It was later reduced to make room for the present world. Following this Reduction, the lights of Divinity were accumulated into "Sefirot", the vessels which contain the immense Divine lights. The three upper "Sefirot" did their job. But the lower six broke into many pieces and scattered. This is called in Hebrew: "Shevirat Hakelim" (Breaking of Vessels). Because of this breaking of vessels, good and evil were mixed with each other in the whole universe. The splinters of the divine lights, called "Nitzotzot" (sparks), fell into the depths of "Clippot", the evil powers of impurity. The broken "Divinity" went into exile among the "Clippot". According to Kabbala, the fate of the Jewish people is similar to that of the "Divinity". The Jews are still in exile amongst the nations. The salvation depends on every person. If people succeed in collecting all the "Nitzotzot", the salvation of humanity will come. The collection of "Nitzotzot" will be done by good deeds, such as obeying the Jewish religious rules. When someone does so, he collects "Nitzotzot" and puts them back in place. He then deals with "Tikun Olam", correction of the world.

The Kabbala has a great influence on Judaism, especially on the Hasidim movement. Kabbalic concepts, developed mainly in 16th century Safed, have penetrated the Jewish liturgy. One of them is the "Holy matching". Philosophically, this concept has another meaning, but in the popular cognition it is perceived as a holy marriage treaty between God and the Jewish people.

For example, the "Shavuot" holiday, in which the Holy Torah was given by way of a pact between God and the Jews, has been compared to such a holy marriage. Also the customs of "Kabbalat Shabbat", (receiving Sabbath), were changed following the Safed notion of "Holy matching". The Kabbala followers in Safed started in the 16th century the custom of going Friday before sunset out of town, wearing white clothes, to receive the bride, Shabbat. Friday night was the link between God (the king) and Shabbat (the queen). Following the mystical marriage, souls of righteous people were born. This custom of going out of town Fridays was abolished after the fall of the Safed centre in the beginning of the 17th century, but its influence is felt until today the Alkabetz poem "Lecha Dodi", mentioned above.

HaAri Hakadosh said that "the Shechinah (the presence of God) rests above Safed". You can feel it even today. Its clear air and serenity helps visitors to contemplate about the philosophical subjects I have just mentioned, and others. It is worth visiting this place even if you do not have the faintest idea what you are going to do there.