Halakhah sa Exodo 22:12: Mishneh Torah, Sabbath

In the Torah, it states (Exodus 23:12, et. al.), "you shall rest." [Hence] one is obligated to rest even from things that are not constructive labor (melakha). And there are many things that were forbidden by the Sages and deemed a shevut (a restriction decreed by the Sages regarding Shabbat). Some of them are things forbidden because they are similar to constructive labors, and some of them are things forbidden as a decree lest one go from them to [doing] that which is forbidden [and would result in the punishment] of stoning. And these are them:

The Sages forbade moving some things on Shabbat in the way that he does on [weekdays]. And for what reason did they [promulgate] this prohibition? They said, "And just like the prophets prohibited and commanded that your going on Shabbat not be like your going on [weekdays] and that the speech of Shabbat not be like the speech of [weekdays]—as it is stated (Isaiah 58:13), 'and speak a word'—all the more so should the carrying of Shabbat not be like the carrying of [weekdays. This would be] so that it not be like a [week]day in his eyes, and he come to pick up and fix vessels from one corner to another or from one house to another, or store rocks, and that which is similar to it. As he is surely idle and sits in his house and will seek something with which to occupy himself. And it will come out that he would not have rested, and would nullify the reason [for Shabbat]; as it is stated (Exodus 22:12 and Deuteronomy 5:13), 'in order that he will rest.'"