The Gemara cites what we learned with regard to the following passage:
“If you keep your feet from breaking, from pursuing your affairs on My holy day, and you call Shabbat a delight, the Lord’s holy day honorable, and you honor it by not going your own way, from attending to your affairs and speaking idle words” (Yeshayahu 58:13).
The Rabbis derived:
– from the words “and you honor it” that your dress on Shabbat should not be like your dress during the week, as Rabbi Yoḥanan would refer to his clothing as my honor, indicating that appropriate clothing is a form of deference.
– from the words “going your own way” mean that your walking on Shabbat should not be like your walking during the week.
– “From attending to your affairs” means it is prohibited to deal with your weekday affairs and to speak about them on Shabbat. However, affairs of Heaven, i.e., those pertaining to mitzvot, are permitted.
– “And speaking idle words” means that your speech on Shabbat should not be like your speech during the week, i.e., one should not discuss his weekday affairs on Shabbat. However, it is only speech that they said is prohibited, whereas merely contemplating weekday affairs is permitted.
A midrash is cited in Tosafot that is also brought in the Jerusalem Talmud. It states that the Sages prohibited speaking excessively on Shabbat. Some commentaries wrote that people should not exert themselves on Shabbat, even to discuss Torah matters. In the Adderet Eliyahu it is suggested that the Gemara means to say that one should not speak in languages other than Hebrew. This custom was observed by many over the generations.
The Gemara discusses how one’s walking should differ on Shabbat from the rest of the week, concluding that pesia gassa – taking large steps – is prohibited.
The Hebrew word gassa, which means large in this context, literally means “crass.” People who take large steps on Shabbat create the impression that they are rushing to their business, which is obviously inappropriate on Shabbat. Consequently, the phrase pesia gassa literally means “a crass step.” The Gemara states that taking large steps detracts from one’s vision. Some commentaries interpret the idea of one’s vision returning to him at kiddush to mean that resting on Shabbat heals that which was damaged during the week’s exertions.