In order to carry from one’s home into the street (even when the area is enclosed by a properly constructed eruv), the eruvin ceremony must be performed. This ceremony involves the placing of food in one designated home on behalf of all Sabbath observers in the enclosed area. In order for the eruvin ceremony to be valid, however, it must be performed on behalf of all owners of streets and homes in the enclosed area.

The purpose of the eruv is to enclose on all sides the area in which one wants to carry, so that it becomes a private domain, a reshut hayachid. If the area in question is a karmelit, a space that qualifies neither as a public domain nor as a private domain, gaps in the eruv structure may be bridged by means of a constructive or symbolic doorway called tzurat hapetach. A tzurat hapetach is made up of two posts, each called a lechi, and a crossbeam or overhead wire called a korah.

“On Shabbat, every person must remain in his residence,” said Moshe to the people, forbidding them to walk more than a certain distance beyond their desert encampment. This distance, which measures two thousand amot – about two thirds of a mile – is known as techum Shabbat. It is the same distance that stretched from the perimeters of the Levite cities to their outlying suburbs.

In the movie “The Paper Chase,” a Harvard student rips out a page of the law report so that his fellow student will be unable to read it and will come to the lecture unprepared. About 2,000 years earlier a student lay feverishly ill in the academy of Rabbi Akiva in Bnei Brak. So caught up were the other students in the competitiveness of their learning that they found no time to visit him or take care of him. As the student lay dying, Rabbi Akiva himself entered the sick room, fed him, made him comfortable and swept the dust from the floor. The sick student survived. His peers did not.

Football’s 49ers rarely drop the ball. But how many of us make it through 49 nights from the second night of Pesach all the way to Shavuot without losing count? Sometimes we never even make it to the first yard line. We are so busy preparing for second night Seder that we miss evening prayers in shul and forget to count Day One.

What is chametz? What are the various categories of chametz? Does the prohibition of chametz on Pesach apply also to non‑food products? Can medication containing chametz be taken on Pesach? Can vitamins produced with no Pesach supervision be used? What about liquid medicine such as cough mixture? Can non- supervised body soap or liquid detergent be used? What about toothpaste? May one use rubbing alcohol? May one eat egg matzah?