The mikdash, the tabernacle, had virtually no “practical” application. It existed, instead, purely for religious and symbolic purposes. It thus follows that each of the details given to us in the Torah are there for a reason – not for aesthetics, but for the underlying purpose of the mikdash, to teach us how to be holy.
One of these details is the “rim” the zar that is required on certain items.
The Ark: shalt make upon it a zar of gold round about.
The Table: make for it a zar of gold round about. … and its crown: thou shalt make a golden crown for its zar round about.
Incense Altar: thou shalt make for it a rim of gold round about.
These words are repeated when the items were actually made, so they appear in the text of the Torah a total of eight times. Eight is the number representing man’s connection with the divine. So there is something about the zar that refers to a relationship with G-d.
But what is the symbolic meaning of a zar?
Perhaps we can answer this by looking at how the word is used elsewhere in the Torah. Here are a few examples:
.. but a stranger (zar) shall not eat of them, because they are holy. (Ex. 29:33) You shall offer no strange (zar) incense on it. (30:9) whoever puts any of it upon a stranger (zar), shall even be cut off from his people. (30:33) And Nadav and Avihu, the sons of Aharon, took each of them his censer, and put fire in it, and put incense on it, and offered strange (zar) fire before the Lord, which He commanded them not. (Lev. 10:1) the stranger (zar) that comes near [the tabernacle] shall be put to death. (Num. 1:51)
Zar is used to refer to things that are not allowed to be in contact with holiness!
We have other words for “stranger” or “non-Jew” in the Torah. But this word, zar, is uniquely used as something that must be separate from holy things.
What does that have to do with a rim?
Could the answer be as simple as suggesting that the ark, incense altar, and the table have rims to tell us that the essence of that object must not be adulterated by an outsider?
The ark represents close relationships (brothers, husband and wife, man and G-d). That the ark had a rim could teach us that these relationships are meant to be exclusive. A man and wife should not share their marriage with someone else. In the same way, idols are not welcome in the relationship we have with our Creator.
The incense altar, connected as it is to our nostrils (where Adam was ensouled), and to the mystical nature of the connection we have with G-d, is similarly encircled by a rim. We should remember that our relationship is direct, and excludes the zar, the stranger.
And the table, connected as it is to the lessons of Eden (email me for details) could be a reminder that we must be particularly vigilant to not follow after our eyes and our base desires, but instead must always be doubly careful before acting on impulse. The table has two rims – and I think it is because we must deal with the fact that our desires occupy a special part of our psyche: we are most likely to rationalize our desires as somehow justified (just as Chava did).
But wait! There are also major elements of the mikdash that have no rim! The Menorah has no rim. And neither does the copper Altar (for normal offerings). Why not?
Could the reason for this be consistent with the above: The Menorah represents light in all of its symbolic meanings: illumination, knowledge, revelation, etc. The Menorah is not just for the Jews! It is instead meant to be a light for the whole world. And so it does not have a rim, an exclusionary zar.
The copper altar represents the opportunity to elevate the physical world into the spiritual realm – connecting heaven and earth, repairing the split caused on the Second Day of Creation. And this, too, is not uniquely for the Jewish people. A non-Jew can bring an offering, an elevation-offering (olah) just as Noah did. The elevation offering is specifically to elevate the physical plane. Elevating the world is not uniquely for Jews! Which might explain why it, too, lacked a zar?