Some actions are permitted on Shabbat by Torah law but prohibited by the Sages due to their having the appearance of a transgression of Torah law. The purpose of these prohibitions is to prevent error, lest one see people performing such an action, and be led to believe that a similar, prohibited act is also permissible. Furthermore, these prohibitions also serve to prevent false suspicions, as onlookers might think that the person is guilty of performing a prohibited labor.

Further reading: For more on prohibitions due to the appearance of transgression, see p. 454.

Prohibitions that stem from a concern for the appearance of transgression are not exclusive to Shabbat; they exist in a variety of halakhic areas. There is nevertheless a particularly long list of actions that are prohibited on Shabbat for this reason. Two examples which express the aforementioned reasons for the prohibition are as follows:

If a garment became wet during the course of Shabbat, it is prohibited to hang it out to dry on a clothesline on Shabbat, so that people will not mistakenly think that these clothes were washed on Shabbat and that laundering is permitted on Shabbat.

It is prohibited for a Jew to rent out his place of business that bears his name, to a gentile who would operate it on Shabbat. In this case, the reason for the prohibition is that people might suspect the Jew of desecrating Shabbat.