The prohibition of commercial activity on Shabbat is one of the earliest known decrees enacted by the Sages to protect Torah law. This decree is generally explained as a protective measure to prevent writing on Shabbat, as commercial activity generally requires writing in order to record and approve legally binding transactions. Although Torah law does not prohibit commercial activity itself on Shabbat, commercial transactions often entail numerous activities that are prohibited on Shabbat, such as carrying objects from one domain to another, fixing utensils or completing their production, and handling objects that may not be handled on Shabbat.
As the decree prohibiting commercial activity was already widely known and accepted in talmudic times, this chapter examines the scope of the prohibition and seeks to determine precisely which activities fall under the decree. In addition to prohibiting direct and explicitly formulated business transactions, the decree also encompasses related activities, such as hiring workers and granting or receiving a loan. However, since the source of this prohibition is rabbinic, there are instances where there is room for leniency, such as when the commercial activity is for the sake of a mitzva or when there is no concern for possible violation of Shabbat.
An example appears in the first Mishna of the perek:
One may borrow jugs of wine and jugs of oil from another on Shabbat, as long as one does not say the following to him: Loan me. And similarly, a woman may borrow from another loaves of bread on Shabbat. And if the lender does not trust him that he will return them, the borrower may leave his cloak with him as collateral and make the proper calculation with him after Shabbat. And similarly, on the eve of Passover in Jerusalem, when it occurs on Shabbat, one who is procuring a Paschal lamb may leave his cloak with him, i.e., the person from whom he is purchasing it, and take the lamb to bring as his Paschal lamb, and then make the proper calculation with him after the Festival.