THE GEMARA STATES THAT IF PURIM FALLS OUT ON SHABBOS, EVEN THOUGH THE MEGILA IS NOT READ, YOU SHOULD STILL LEARN ABOUT THE STORY OF PURIM, ITS HALCHOS ETC.
THE GEMAMRA THEN SAYS THIS IS CLEAR- WE KNOW THAT WE HAVE A REQUIREMENT TO LEARN ABOUT PESACH ON PESACH, ATZERET ON ATZERET AND CHAG BCHAG. THE GEMARA ANSWERS THAT ON PURIM THAT FALLS ON SHABOS WE MAY HAVE THOUGHT THAT WE DONT LEARN THE STORY AND HALACHOS BECAUSE WE MIGHT COME TO BE OVER THE GEZEIRA OF RABAH ABOUT CARRYING. THE GEMARA ANSWERS THAT WE DONT WORRY ABOUT IT.
WHY IS THERE A GREATER CHASHASH ABOUT BEING OVER THE GZEIRA ON PURIM AS OPPOSED TO THE OTHER HOLIDAYS THAT THE GEMARA WOULD NEED TO SPECIFICALLY MENTION THE REQUIREMENT?
ARI, NEW YORK, NY
The Chashash on Purim is that if you learn about Purim on Shabbos, you may come to carry the Megilah (which contains the story) and which the Chachachim forbade because of the Takanah of Rabah. This Chashash is not applicable on Yom tov. What are you worried about, that one might come to carry a Sefer Torah? But a Sefer Torah is not Muktzah on Shabbos, because unlike a Megilah, everybody knows how to Lein it (and even if they don't, it is not a personal obligation to read it, just a communal one, so whoever does not know how to do so will not be asked to).
b'Virchas Kol Tuv,
Eliezer Chrysler