The prayer book is among the most widely-circulated and best-known of Jewish books. While the roots of Jewish prayer can be found in the Hebrew Bible, the fundamentals of the synagogue service as we know it today were initially described in the rabbinic literature of the first centuries of the common era. The Siddur (containing the daily and Shabbat prayers) and the Mahzor (containing holiday prayers), did not emerge as separate texts and as compendia of Jewish liturgy until the period of the Geonim, the heads of rabbinic academies in Babylonia in the early Middle Ages. In the ninth through twelfth centuries, localized rites also emerged among Jewish communities in Germany (Ashkenaz), Northern France, Italy, the Byzantine empire, Provence, Muslim Spain (Sepharad), and Yemen.

At the end of the Middle Ages, two important developments, migration and printing, had a major impact on the history of the Siddur. Demographic shifts resulting from expulsions and from other migrations led to the formation of new Jewish communities in Eastern Europe, Italy, and the Ottoman Empire. Immigrant Jews brought their local liturgies with them, but many of these rites did not survive as it became impossible for each group to maintain a separate synagogue in each community. Some communities, however, such as Frankfurt-am-Main, continued to use a local rite until the twentieth century.

The text of the prayers offered in this siddur is that which we have inherited from our forebears. Any worshiper who wishes to adhere to that text will be able to do so effortlessly as regards all the central and principal elements of the service. However, we should not hesitate to amend the text of the prayers or to add to it when this was dictated by ideology. Some of those who worship in our congregations wrongly think that the text of the prayers is somehow sacredly immutable, that its words can never be changed - rather like a Sefer Torah. This is far from being the halakhic situation.

In the Laws of Reciting the Shema 1:7, Rambam states: "These benedictions, together with all the other benedictions in general use among Jews ... nobody may subtract from them or add to them. Where it has been instituted to end [the benediction] with Barukh or not to do so, we may not do otherwise ... the general rule is that anyone who deviates from the template instituted by the sages as regards benedictions is in error, and must recite the benediction once again according to the template." We should note that Rambam is here forbidding deviation from the template instituted by the sages for prayer, but not from a specific text. The template, it would appear, refers to the structure of the service - that the Evening Recitation of the Shema must be preceded by two benedictions and followed by another two; that the subject of the first one must be bringing on eventide - and so forth. In this siddur I have been scrupulous in this matter of not deviating from the template, and it contains no alteration of the template of the services, no deviation from the accepted order and contents of the enedictions and the prayers. It follows that the interdiction of altering the template of the prayers does not affect their literary content.

Rashba [Rabbi Shelomo ben-Adret] writes [on Berakhot 11a]: "The statement of the sages that we may not increase or decrease [the benedictions] does not refer to increasing or decreasing their verbal content; if that were the case they should have instituted an exact text for each benediction, and that is something that we do not find anywhere ... As regards the benedictions, the sages set no particular number of words that the worshiper must say, no more and no less." It is also well known that some of our most illustrious sages composed hymns to be added into existing benedictions, even making an incidental change in the accepted text. From the halakhic point of view this is perfectly permissible according to the vast majority of the decisors. If it were forbidden to deviate from an unchanging and predetermined text, all the hymns and piyutim (Poetry) would be forbidden, which of course it is not.

Though it is of utmost importance in our Siddurim, which are primarily a compendia of the history of our connection with God, to maintain the prior traditions of our ancestors, the sources do give us permission to make changes, add new interpretations and take advantage of newer history to make our personal and community reflections about God more relavant to the modern worshipper. Remember, the Siddur is, only, a guide to prayer, not the Torah of prayer. It is not possible that someone edit a siddur and not leave on it some personal imprint, agenda or predjudice. It is only understandable that any particular siddur may contains emphases, innovations, changes and retentions that will not be pleasing to everyone. Therefore, remember, it is best to use a siddur as the general text for worship while adapting the specific edition one needs to use in services to ones own understanding of the of the unique personal relationship with God.