Question:

Many libraries stamp their names on the edges of the pages of their books. Is opening or closing such a book considered erasing or writing, and therefore a violation of the Shabbat laws?

Answer:

Writing and erasing are two of the 39 creative acts which are forbidden on Shabbat. The question is whether closing such a book is considered writing—since that renders the letters readable; and if opening it is considered erasing—since the letters then become unreadable.

Rabbi Mordechai Jaffe (1530-1612), commonly referred to by the title of his magnum opus, the Levush, writes that opening and closing such books is indeed forbidden on Shabbat.1 The rationale behind this ruling is that although the reader has absolutely no intention to either form or erase the letters, this is the inevitable result of opening or closing such books.2

However, this view is not universal and a number of other authorities3 rule that since the letters exist regardless of their visibility, and can appear and disappear with virtually no effort, opening and closing the book is not considered to be dynamic and is therefore permissible, similar to the Halacha that closing and opening a door is not considered building or demolishing.

The Halacha follows the latter opinion, and the books may be opened and closed.

However, some follow the opinion of Rabbi Yisrael Meir Kagan (1838-1933) who cautions that that if there are other books available, the stamped books should be avoided.4

The above discussion concerns Torah books and other permissible readings. Books read on Shabbat must be compatible with the sacred atmosphere of the day as specified in the Code of Jewish Law.5