Ner tamid

A sanctuary lamp, chancel lamp, altar lamp, everlasting light, or eternal flame is a light that shines before the altar of sanctuaries in many Christian places of worship. Prescribed in Exodus 27:20-21 of the Torah, this icon has taken on different meanings in each of the religions that have adopted it. The passage, which refers to prescriptions for the tabernacle, states:

In Judaism, the sanctuary lamp is known by its Hebrew name, ner tamid (Hebrew: נֵר תָּמִיד‎), which is usually translated as "eternal flame" or "eternal light". Hanging or standing in front of the ark in every Jewish synagogue, it is meant to represent the menorah of the Temple in Jerusalem as well as the continuously burning fire on the altar of burnt offerings in front of the Temple. It also symbolizes God's eternal presence and is therefore never extinguished. It is also intended to draw parallels between God and fire, or light, which is emphasized throughout the book of Exodus in the Torah.

These lights are never allowed to dim or go out, and in the case of electric problems, alternative emergency energy sources are used to prevent it from diminishing.

Though once fueled by oil, most today are electric lights, including some that are solar-powered.

The eternal light is central to one of many stories behind the celebration of the Jewish festival of Hanukkah. When the ancient Maccabees rebelled and reclaimed the Temple in Jerusalem, they rekindled the eternal light. However, there was only enough oil to keep the flame burning for one day, and it took eight days to bring new oil. Miraculously, according to the story as recounted in the Talmud, the flame continued to burn until the new oil arrived.

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