The Mishna enumerates thirty-nine "Avot" or principal acts of labor, the performance of any one of which constitutes a violation of the Shabbat. Every other kind of work becomes illegal only if it can be classified under one or any of these principal acts of labor. Thus, for instance, under the principal act of ploughing, every analogous kind of work, such as digging, delving, weeding, dunging, etc., must be classified. In addition to these thirty-nine principal acts and their accessories and derivatives, there are other acts which are especially prohibited by the rabbinical law as tending to violate the Shabbat rest (Shevut). For the violation itself various degrees of culpability are established, and various degrees of punishment awarded. All these subjects relating to the due observance of the Sabbath, and pointing out its violation in every possible way, form the contents of the treatise Shabbat. More...