Study Guide Shabbat 70 Today's shiur is dedicated for a refuah shleima for Netanel Ilan ben Shayna Tzipora and by Judy Shapiro in honor of all her children.  Why is there a difference between if one forgot it was Shabbat one brings one sacrifice and if one forgot melachot one brings a sacrifice for each? From where do we derive that one brings a separate sacrficie for each melacha that one performed? Shmuel brings a source and the gemara assesses why he did not bring one of the two sources offered by the tannaim Rabbi Natan and Rabbi Yosi. Rabbi Natan and Rabbi Yosi debate why the verse regarding fire was singled out - was it to create a paradigm for all the melachot or was it singled out because it is different (less stringent than all the others)? What does Rabbi Yosi derive from the words "from one from these?" How many sacrifices does one bring if one forgot it was Shabbat and forgot that melachot were forbidden? If one did two melachot two times - once forgetting it was Shabbat and once forgetting melachot and finds out about one before the other, can one sacrifice cover all the actions? Different permutations are brought.