One of the oldest symbols of the Jewish faith is the menorah which is a seven-branched candelabrum used in the Temple. The kohanim lit the menorah in the Sanctuary every evening and cleaned it out every morning, replacing the wicks and putting fresh olive oil into the cups.
It has been said that the menorah is a symbol of the nation of Israel and it is the Jewish faith's mission to be "a light unto the nations."The lamp stand in today's synagogues, called the ner tamid (the continual lamp, usually translated as the eternal flame) symbolizes the menorah. The nine-branched menorah used on Chanukah is commonly patterned after this menorah, because Chanukah commemorates the miracle that a day's worth of oil for this menorah lasted eight days. The menorah in the First and Second Temples had seven branches. After the Temples were destroyed, a tradition developed not to duplicate anything from the Temple and therefore menorah's no longer had seven branches. The use of six-branched menoras became popular. In modern times, some rabbis have gone back to the seven-branched menoras, arguing that they are not the same as those used in the Temple because today's menorah are now electrified.