Before the book, there was the scroll. The book, in the form of a codex, where pages are bound together, is easier to handle. One can turn to desired passages without unrolling and seeking. Books are also much easier to produce and to store, whether in manuscript or in print, so, in the course of time, the book replaced the scroll, but in Jewish usage not completely. The scroll was retained for use in synagogue worship: the reading of the Pentateuch on Sabbath and holidays and the weekday services on Monday and Thursday may be done only from a Torah Scroll. The reading of the Book of Esther on the eve and morning of the Festival of Purim is done from a scroll called Megillat Esther, or just Megillah, the Hebrew for scroll.
Every detail in the preparation of a Torah Scroll is prescribed by law. "Prepare a beautiful Sefer Torah" the Talmud admonishes, "written in good ink with a fine pen by an expert sofer [scribe]." Only the skirt (parchment) of a kosher animal may be used. The ink may not contain metal, nor may the scroll be written with a metal instrument, for metal can be forged into weapons which take life while the Torah gives life. Only the words of the Torah may be inscribed on the scroll: neither instructions, nor commentary, nor illustrations, nor illuminations are permitted. The scribe must be learned and pious and must exert the greatest care in assuring correctness, copying from an examined text, not from memory. He must pronounce every word before writing it, and must make sure that his letters are well formed and that there is sufficient space between them, "so that even an ordinary school boy" can readily distinguish between even similar letters. Before writing the name of God, the scribe must state, "My intention is now to write the Holy Name"; then he must inscribe it without interruption. Should he err, he may not erase the mistake; the whole sheet must be put away, to await later reverential interment in consecrated earth. Rabbi Ishmael admonished a scribe, "be careful in thy work, as it is heavenly work, lest thou err in omitting or adding one iota, and so cause the destruction of the whole world."
There is therefore remarkable uniformity in copies of the Torah scrolls, the only differences being in the size of the scrolls, the number of lines, the calligraphy, and whether the scroll is made of parchment or leather. In the Ashkenazi community (Jews living in Christian lands or their descendants), the Torah is written on parchment in letters where horizontal strokes are broad and vertical strokes thin. In Sefardi communities (Jews living in Islamic lands or their descendants), the Torah scroll is often made of leather and the letters are of uniform thickness. The scroll in the Library of Congress is a superb example of a Sefardi Torah. Its supple leather is golden in hue; the jet-black ink of the expertly fashioned letters is in an extraordinary state of preservation, which makes this a distinguished example of the North African Torah scrolls produced in the seventeenth through the nineteenth centuries.