Today's daf is sponsored by Hannah Piotrkowski in honor of Amy Cohn and Karen Kirschenbaum for their gracious hosting and teaching at the Jerusalem Yevamot siyum.  One should not engage in relations with one's wife for the first time on Friday night or Saturday night. Friday night - out of concern for tearing her hymen and causing her to bleed, which is forbidden on Shabbat. Saturday night - out of concern one will do calculations on Shabbat of expenses for the wedding. Why is that an issue if one is allowed to do calculations for a mitzva? All sorts of things that are either mitzvot or have to do with communal needs are permitted on Shabbat. Therefore that explanation is rejected and a different one is brought. The concern is that one may slaughter a young bird on Shabbat. Why is this not a concern when Yom Kippur falls on a Monday? Two distinctions are made - regarding Yom Kippur, there is more time (Sunday) and it is for oneself and not for others. This explanation (concern about slaughtering a bird) could also explain why one shouldn't get married on Friday. If one is supposed to get married on Wednesday, can the marriage be consummated on Wednesday or should they wait until Wednesday night so that if she is not a virgin, he will not change his mind by the next day and not go to court? To answer the question, they bring in Bar Kapara's opinion that connects between the creation of the world (the commandment to be fruitful and multiply - to the fish on Thursday and to humans on Friday) and the days on which virgins and widows are to marry. Widows marry on Thursday for another reason - the rabbis instituted it so that the husband would have three days to spend celebration with his wife before he goes back to work. Other drashot of Bar Kapara are brought. One discusses the greatness of the actions of the righteous and the other, the importance of closing your ears to hearing things that are best not to be heard. When a woman's hymen tears during intercourse, is that considered inflicting a wound on someone and therefore forbidden to do on Shabbat or is it perceived that the blood was collected there and one is just allowing it to leave. Further questions are asked according to each option relating to famous debates between Rabbi Yehuda and Rabbi Shimon regarding melachot that one does on Shabbat that one did not intend or destructive acts.