On Sunday, the eve of Tu Bishvat, thousands of families, inspired by the Kabbala, conducted a ceremonial eating of fruits. The custom, developed by the kabbalists of Safed in the 16th and 17th centuries, includes 30 types of fruits eaten along with the reciting of passages from the Zohar. According to Rabbi Yitzhak Batzri, there are three groups of 10 fruits. Each group of 10 corresponds to a separate world. The world of action (asiya) is represented by fruits with a shell or peel such as nuts and citrus fruits. In this world connection with God is impossible. This is demonstrated by the outer shell or peel. The world of formation (yetzira) is represented by fruits with a pit, which symbolizes a world in which God's inner essence is hidden. The world of creation (briya) is represented by fruits such as grapes and figs that have no big pits. In this world there is only goodness. Batzri said that the custom of drinking four cups - one of white wine, one of white wine with a drop of red wine, one of red wine with a drop of white wine and one of red wine - was introduced later by secular Jews and is not part of the original ceremony. Traditional Orthodox families, mostly Sephardi, have celebrated the custom of the 30 types of fruits for generations. In the Hassidic courts the custom is to conduct the ceremony at large gatherings with the rebbe. In Tel Aviv a kabbalistic ceremony was conducted at the Awareness Center for over 100 people, many of them secular, by students of Rabbi Mordechai Sheinberger. Sheinberger, himself a student of Rabbi Yehuda Ashlag, who wrote an interpretation of the Zohar called Hasulam (The Ladder), uses Kabbala to bring secular Jews closer to Judaism. According to David Agmon, who organized the ceremony in Tel Aviv, the exact details of the Tu Bishvat feast are unclear.