There are many laws that the rabbi developed associated with what is called today “the holiday of Passover,” which were developed for the most part from the simple Torah mandate that no unleavened product may be in the home during the seven-day holiday of the “Feast of the Unleavened Bread.” But things are not what they seem.
Actually, the biblical holiday Passover, Pesah in Hebrew, no longer exists. Passover was a one-day holiday that occurred on the 14th day of the first month whose observance was to sacrifice and eat a Pascal lamb. When the temple was destroyed in 70 CE by the Romans and sacrifices ceased, so did Passover. Jews decided to recall this now non-existing holiday by renaming the seven-day holiday “Feast of the Unleavened Bread” that the Bible states begins the day after Passover on the 15th day of the first month by the name of the now non-existing holiday “Passover.” However, in the Siddur and prayers the holiday “Feast of the Unleavened Bread” is still called by its biblical name, not Passover.
What laws did the rabbis develop for the resurrected holiday Passover?
“Laws of Pesah” by Rabbi Eliezer Melamed is a comprehensive volume telling the laws and explaining them. It is easy to read and has good explanations of the many rabbinical laws. The book is an English translation of the Hebrew original that sold over 300,000 copies. The author is one of the most popular educators in Israel. He is a rabbi of a Hesder yeshiva, a school that recognizes that Israeli religious Jews are obligated, as are their non-religious brethren, to serve in the Israeli military and aid in defending their country.
The book is composed of sixteen chapters in which Rabbi Melamed mentions the opinions of various rabbis and discusses, among much else, the meaning of Pesah, matzah, and Seder, the rules concerning the prohibition of unleavened bread, how to get rid of unleavened bread, the practice of searching for unleavened bread, selling unleavened products, why even a drop of an unleavened product renders a food forbidden, can one eat egg matzah, the use of medicines on Pesah that have unleavened ingredients, the meaning of the many practices associated with the reading of the haggadah and the Seder plate, why four cups of wine, and what is the afikoman. His explanations are very enlightening and interesting.
Rabbi Melamed does not take the approach in his book that one has to observe the discussed practice in a particular way and he does not insist that Jews should observe the strictest rabbinical ruling. For example, in regard to eating the afikoman, a piece of matzah at the end of the festive Passover meal, called the Seder, Rabbi Melamed informs readers that the ancient rabbis differed why the matzah is eaten. Some say that the eating of the matzah at the Seder end is the way Jews fulfill the biblical command to eat matzah on the holiday. Others say that the afikoman matzah reminds Jews of the Pascal sacrifice that was mandated by the Torah to be brought in the Temple on the 14th day of the first month, the original Passover, and was brought until the Temple was destroyed in 70 CE. All of the ancient rabbis agreed that this matzah must be eaten while reclining to the left side as a sign of relaxing and freedom. However, the rabbis differed what one should do if one forgot to lean. Some say the person should eat another matzah while leaning, while others say the person must not eat another matzah, and Rabbi Melamed explains both opinions. The rabbi also discusses how much matzah a Jew must consume as the afikoman. He offers a lenient ruling: one can eat the smaller portion, and he explains why.
In short, Rabbi Melamed’s book is filled with clear information about Passover practices and how they are implemented.
 I tell this story in detail in my book “Mysteries of Judaism,” published by Gefen Publishing House. Rabbi Melamed’s book does not discuss this history.
 The holiday of the “Feast of the Unleavened Bread.”