Aravah is a leafy branch of the willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

 tree. It is one of the Four Species (arba'ah minim - ארבעת המינים) used in a special waving ceremony during the Jewish holiday of Sukkot

Sukkot

Sukkot is a Biblical holiday celebrated on the 15th day of the month of Tishrei . It is one of the three biblically mandated festivals Shalosh regalim on which Hebrews were commanded to make a pilgrimage to the Temple in Jerusalem.The holiday lasts seven days...

. The other species are the lulav (palm

Arecaceae

Arecaceae or Palmae , are a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates...

 frond), hadass

Hadass

Hadass is a branch of the myrtle tree that forms part of the lulav used on the Jewish holiday of Sukkot....

(myrtle), and etrog

Etrog

Etrog refers to the yellow citron or Citrus medica used by Jews on the week-long holiday of Sukkot.While in modern Hebrew this is the name for any variety of citron, its English usage applies to those varieties and specimens used as one of the Four Species...

(citron

Citron

Not to be confused with Cintron.The citron is a fragrant citrus fruit, botanically classified as Citrus medica by both the Swingle and Tanaka systems...

).

The aravah is also used for a separate ceremony on Hoshanah Rabbah

Hoshanah Rabbah

The seventh day of the Jewish holiday of Sukkot, 21st day of Tishrei, is known as Hoshana Rabbah . This day is marked by a special synagogue service, the Hoshana Rabbah, in which seven circuits are made by the worshippers with their lulav and etrog, while the congregation recites Hoshanot...

, the last day of Sukkot, when five branches are beaten against the ground to the accompaniment of special verses.

The aravah tree typically grows by the side of a river, although in Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

 it grows wild in many people's backyards. The branches grow long and are lined with long, narrow leaves. Since this tree requires much water to grow, the picked branches dry out within two or three days. In order to keep them fresh as long as possible for the mitzvah

Mitzvah

The primary meaning of the Hebrew word refers to precepts and commandments as commanded by God...

 of the Four Species, they are kept in the refrigerator until use, or wrapped in a moist towel.

On each of the seven days of Sukkot (excluding Shabbat

Shabbat

Shabbat is the seventh day of the Jewish week and a day of rest in Judaism. Shabbat is observed from a few minutes before sunset on Friday evening until a few minutes after when one would expect to be able to see three stars in the sky on Saturday night. The exact times, therefore, differ from...

), two aravah branches are bound together with the lulav and hadass (this bundle is also referred to as "the lulav"). Together with the etrog, these Four Species are then waved in all four directions, plus up and down, to attest to God's mastery over all of creation, and to symbolically voice a prayer for adequate rainfall over all the Earth's vegetation in the coming year. (See Four Species

Four Species

The four species are four plants mentioned in the Torah as being relevant to Sukkot. Karaite Jews build their Sukkot out of branches from the four specified plants , while Talmudic Jews take three types of branches and one type of fruit which are held together and waved in a special ceremony...

 for the complete description and symbolism of the waving ceremony.)

During the morning prayer service in the synagogue

Synagogue

A synagogue is a Jewish house of prayer. This use of the Greek term synagogue originates in the Septuagint where it sometimes translates the Hebrew word for assembly, kahal...

 on Hoshanah Rabbah, after the waving of the Four Species, a separate bundle containing five aravah branches are taken in hand by each worshipper. A series of liturgical verses are read, ending with, "Kol mevasser, mevasser ve-omer" (A voice brings news, brings news and says)—expressing hope for the speedy coming of the Messiah

Messiah

A messiah is a redeemer figure expected or foretold in one form or another by a religion. Slightly more widely, a messiah is any redeemer figure. Messianic beliefs or theories generally relate to eschatological improvement of the state of humanity or the world, in other words the World to...

. Then the bundle of aravah branches are beaten against the ground until many of the leaves have fallen out. The reasons for this custom are steeped in Kabbalah

Kabbalah

Kabbalah/Kabala is a discipline and school of thought concerned with the esoteric aspect of Rabbinic Judaism. It was systematized in 11th-13th century Hachmei Provence and Spain, and again after the Expulsion from Spain, in 16th century Ottoman Palestine...

. The aravot may then thrown away, used before Passover

Passover

Passover is a Jewish holiday and festival. It commemorates the story of the Exodus, in which the ancient Israelites were freed from slavery in Egypt...

 to burn the Chametz

Chametz

Chametz, also Chometz, and other spellings transliterated from , are leavened foods that are forbidden on the Jewish holiday of Passover. According to Jewish law, Jews may not own, eat or benefit from chametz during Passover...

, or are sometimes placed in water in order to grow new aravot trees.

The Aravah ceremony in the Temple

According to the Mishnah

Mishnah

The Mishnah or Mishna is the first major written redaction of the Jewish oral traditions called the "Oral Torah". It is also the first major work of Rabbinic Judaism. It was redacted c...

, In the days of the Temple in Jerusalem

Temple in Jerusalem

The Temple in Jerusalem or Holy Temple , refers to one of a series of structures which were historically located on the Temple Mount in the Old City of Jerusalem, the current site of the Dome of the Rock. Historically, these successive temples stood at this location and functioned as the centre of...

, willow branches were collected from Motsa near Jerusalem and piled upright on the sides of the Altar with their tops bent over the top of the Altar each day of Sukkot. The shofar

Shofar

A shofar is a horn, traditionally that of a ram, used for Jewish religious purposes. Shofar-blowing is incorporated in synagogue services on Rosh Hashanah and Yom Kippur.Shofar come in a variety of sizes.- Bible and rabbinic literature :...

 was sounded, and the worshippers walked about in procession and recited Psalm 117:25, (as is done today as part of the Hashanot ceremony on Sukkot), accompanied by musical instruments (except on shabbat

Shabbat

Shabbat is the seventh day of the Jewish week and a day of rest in Judaism. Shabbat is observed from a few minutes before sunset on Friday evening until a few minutes after when one would expect to be able to see three stars in the sky on Saturday night. The exact times, therefore, differ from...

. In the days of the Temple, the Mishnah reports that after the Aravah ceremony on Hashana Rabba, "the children threw away their lulavim and ate their etrogim (citrons)."