Eruvin 27 - Shabbat September 5, 16 Elul

Rabbi Yochanan taught that any time there is a general rule in a mishna, one can assume that there are exceptions to that rule. Even in a case where exceptions are listed, there may be more exceptions. The gemara learns that this statement was made in reference to the mishna in Kiddushin 29 about women being exempt from time bound mitzvot and obligated in non time bound commandments. The gemara then lists a number of exceptions to that rule. The gemara then brings a mishna relating to zav and our mishna which both list exceptions and yet there are more exceptions. There was a statement made either about eruv or about maaser sheni that when our mishna said water and salt, it only meant on their own but salt water can be used. A question is raised regarding salt water for maaser sheni and the response is that it must have oil mixed in. It is coming to teach that if one uses the maaser money to buy salt water mixed with oil, even though salt water is insignificant, since it is mixed with oil, one can use the money to purchase it all even though some of it would not be worthy on its own. The gemara questions this as that law is learned directly from a drasha on the verse relating to maaser sheni. The gemara delves into that drasha and tries to understand what each part of the verse is coming to teach. Rabbi Yochanan understands why each word is there other than "cattle." What is the basis for the debate regarding buying fish from maaser sheni money?