The symbolic meaning of light as an expression of the positive aspect of reality is not confined only to the realm of language.
It is realized also in the use of light and lamps as concrete means of expression, which symbolize and point to an essence that contains holiness, in all its different appearances in reality:
in holiness and at the Holy Temple—in the sanctity of place;
in the Sabbath and festivals—in the sanctity of time;
on special occasions—in the sanctity and importance of the event.
The Temple menorah, with all of its ornate and extremely elaborate craftsmanship, was not there for any practical purpose.
It stood at the heikhal, a windowless hall only seldom frequented by people.
Yet it was there as a symbol of the holiness of that place, of its relation to light.
This menorah—"the sun's sphere" (Yerushalmi, end of Hagigah)— is a sphere of sunlight, which shines through the walls and the curtains.
No wonder, then, that this meaning of the Temple menorah was conceived by the Jewish people as the symbol par excellence of Jewish existence (as can be seen in Jewish ornaments from all periods), from synagogue mosaics in the Galilee to ornaments on utensils in the Roman catacombs, and even, in a sense, to the synagogue itself—the place where an eternal candle burns day and night.
–Rabbi Adin Steinsaltz
From On Being Free by Rabbi Adin Steinsaltz