10. On Shabbos, personal documents, such as bills, account sheets, and
social correspondence, may not even be scanned with one's eyes without
articulation (1). Even though one is only engaging in mental
contemplation, it is, nevertheless, forbidden, because our Sages allowed
mental involvement in one's business affairs, only when it is not obvious
that one is engaged in such an activity (2). In this instance, however, it
is obvious that one is thinking about forbidden concerns, and hence, it is
included in the prohibition of "...pursuing your affairs" (3).
A person who receives a letter and is unaware of its contents may read it,
because it might contain a matter of vital personal concern ("Tzorech
Gufo"). One may not, however, read it aloud. If one is certain that it
involves business concerns alone, it is forbidden even to scan it with
one's eyes. It is also forbidden to handle it, because it is considered
(1) Some say this prohibition was enacted out of a concern that one may
erase part of the contents, thereby violating a biblical prohibition;
others claim that this falls under the general prohibition of "mimtzoh
cheftzechoh" ("pursuing your affairs") which we have been dealing with
throughout this chapter (Mishna Berura 307:51).
(2) See HY 90: 2 and 6.
(3) See HY 90:2
(4) Things which are prohibited to read on Shabbos, are muktzeh (Taz 307:17).