Today's daf is sponsored by Ami Plaksin in honor of his wife, Ilana, who despite her busy life, manages to find time to learn daf yomi.  The mishna lists the sources for the following laws: a women who has semen exit her body within 3 days of having intercourse is considered impure, one can wash an infant within three days of a brit milah even on Shabbat, a red string is tied around the scapegoat on Yom Kippur that turns white as a sign that their sins are forgiven, annointing is forbidden like drinking on Yom Kippur. Several opinions are brought regarding the amount of time semen from intercourse remains live in a woman's body and makes her impure. The opinions are derived from different traditions regarding the days leading up to the receiving of the Torah and how many days the husbands and wives needed to separate before receiving the Torah.