Double Trouble

An acquaintance remarked that this year in Judaism is “the year of the cow.” I did not have the faintest idea of what he was talking about until he explained: “This is the year of two udders (Adars).” Since Purim is such a long way off due to the leap year, people need to amuse themselves even with corny jokes.
If we would pasken like Rebbe Eliezer the son of Rebbe Yose, we wouldn’t have to wait any longer than usual this year for Purim. He holds that the reading of Megillas Esther and the celebration of Purim should take place in Adar Rishon, the month immediately after Shevat. However, the Gemara records that the halachah was decided in favor of Rabban Shimon ben Gamliel, that the Megillah and Purim celebrations should take place in Adar Sheini. Hence, this year being a Jewish leap year, we have to wait an extra month for Purim.
What is the basis of the dispute? The Gemara says that Rebbe Eliezer’s opinion is perfectly understandable. There is a concept of “Ein ma’avirin al ha’mitzvos,” not passing up the opportunity to perform mitzvos. Faced with the choice of observing the mitzvos of Purim in the first Adar or the second Adar, we certainly should choose the first Adar. Rashi cites a source for this concept: The pasuk states, “U’shmartem es ha’matzos,” “you shall safeguard the matzos” (to prevent them from becoming chametz). The Mechilta homiletically interprets this verse as “U’shmartem es ha’mitzvos,” safeguard the mitzvos. Don’t allow the mitzvos to grow old; grab the first opportunity to perform them.