The westernmost of the lights in the menorah
burned perpetually (Talmud Shabbat 22b). (The
menorah stood against the south wall of the
tabernacle, so the westernmost light was the
one on the right end.) The Talmud says that the westernmost light burned perpetually to demonstrate that the Divine Presence dwelt in the Tabernacle.
Aaron relit all the lights in the menorah
every evening, but the westernmost light was the only one that was still burning when he refilled it with oil and trimmed its wick. The oil that Aaron put in the menorah was only enough to burn
all night; the fact that the westernmost light
lasted until the next night was miraculous.
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