A Jewish festival and holiday commemorating the first and most momentous event in Jewish history: the liberation of the Hebrews from bondage in Egypt and the "passing over" of God of the houses of the Isrealites during the tenth plague of Egypt (when the first-born children of the Egyptians were killed). Passover begins on the 15th and ends on the 21st or 22nd day of the month of Nisan (March or April). On these seven (or eight) days, also called the Festival of Unleavened Bread, all leaven is prohibited, and only unleavened bread (matzo) may be eaten. The matzo symbolizes the Hebrews' suffering while in slavery and the haste with which they left Egypt during the Exodus. After the destruction of the Temple in Jerusalem, Passover celebrations became home-based. The first night of Passover is particularly celebratory, with a special family meal called the seder. Symbolic foods commemorating the Hebrews' liberation are eaten at the seder and prayers and traditional recitations are performed. Custom also calls for a place to be set for Elijah, the herald of the messiah. Though Passover is one of great rejoicing, strict dietary laws must be observed, and there are certain restrictions regarding work at the beginning and end of the festival.