This sugya discusses the prohibition of Amira L'Akum on Shabbos and Yom Tov. Aside from the prohibition of performing any work on Shabbos, there is an additional issur of having work done for you by someone else. We discuss the various reasons for this issur, and the many ramifications. One basic concept addressed is the root of the issur of Amirah L'Akum. Is it prohibited simply because one is asking someone else to perform an action that he is forbidden to do, or is it because having someone perform an action for you makes him your Shliach - and essentially it is as if you performed the action yourself?One practical difference is - can one ask a non-Jew "before" Shabbos to perform the action on Shabbos?This sugya is connected to Parshas Bo, as the Pasuk "Kol Melacha Lo Ye-Aseh" (according to the Mechilta) is the source for this issur.