Masechet Shvuot begins with an unusual feature: it doesn’t open with a direct definition of “shevuot” (oaths), but instead with a statement that lists different legal categories that the tractate will cover, including tumah (impurity), bi’at mikdash (entering the Temple in a state of impurity), yediot hatumah (knowledge of impurity), and various types of oaths (shevuot). The Mishna explains that some of these cases involve two that are actually four—referring to the idea that the Torah mentions two, and the Rabbis derive an additional two.






