At a Jewish wedding, the moment the groom hands the ring to the bride is not a romantic gesture or a formality. It is the legal act that creates the marriage. Everything else — the Ketuba, the blessings, the party — comes afterward. That is why Jewish law has so much to say about that ring: what it should be made of, what it should look like, and who it has to belong to.
WHY A RING?
The first thing to understand is that the ring is not required. The Torah never mentions it. Qiddushin is performed by giving the bride something of monetary value, and the minimum the law demands is one peruta, the smallest coin in circulation in Talmudic times. The amount is deliberately tiny, so that no man would be prevented from marrying for lack of money.
So the ring is a custom, not an obligation. A very old custom: Tosafot (Kiddushin 9a) suggests that a ring may already have been used for this purpose in biblical times. And it was never universal. Some Syrian and Iraqi communities used a silver coin instead of a ring, and the Syrian Jewish community of New York still does. In Georgia the custom was to place the ring inside a cup.
Why did the ring win out? For a very simple reason: a ring is worn all the time. It is a permanent reminder of the commitment, unlike a coin, which ends up in a drawer.
There is an image here I find beautiful. Our Sages compared the covenant between God and Israel to a marriage. And every morning, when a Jew puts on Tefillin, he winds the strap around his middle finger and says ve’erastikh li le’olam, “I will betroth you to Me forever.” The same gesture, on the same finger, meaning the same thing.
GOLD, SILVER, AND NO STONES
The common custom is a gold ring. But there is a rule far more important than the material, and it explains everything else: the value of the ring has to be obvious at a glance.
The reason is legal, not aesthetic. Qiddushin is not performed with the ring as an object but with its monetary value. For the act to be valid, the bride must be able to know, at the moment she receives it, what it is she is receiving. Three practical consequences follow:
1. The metal cannot be disguised. No gold-plated rings that are really made of something else. What it looks like has to be what it is.
2. No stones. This is the best-known rule and the one that surprises brides most. A stone is a “blind” object: you cannot determine its value by looking at it. A diamond might be worth a hundred dollars or a hundred thousand, and no one can tell just by seeing it. So the qiddushin ring is plain.
3. No engravings or designs. For the same reason: an inscription or fine metalwork can change the value of the ring in ways that are not easy to calculate.
Some add another reason for avoiding a stone, and it is a very Jewish one: so as not to embarrass the groom who cannot afford one. If everyone uses a plain ring, nobody is exposed. It is the same principle behind recording a uniform sum in every Ketuba, without distinguishing between brides from wealthy families and brides who are not.
One practical clarification. In my community we ask couples to bring a plain ring, but if by mistake they bring an engraved one, we use it without any problem.
THE RING HAS TO BELONG TO THE GROOM
You cannot give as qiddushin something that does not belong to you. That is why the officiating rabbi normally asks the groom, in front of everyone, whom the ring belongs to. It is not an empty formality: he is verifying that the ring is in fact the groom’s, and that he has not already given it to the bride before the ceremony. If the ring was already hers, there is nothing to hand over, and there is no qiddushin.
ONE MORE REASON
There is an additional explanation, brought by Rabbi Aryeh Kaplan, for why a ring was chosen and not some other object. In the Torah, handing over a ring is the gesture of transferring authority. Pharaoh gave his ring to Yosef. Ahashverosh gave his to Haman, and later to Esther. In each case the king was delegating his power over the kingdom.
When a man gives a ring to his wife, he is symbolically doing the same thing: giving her authority over his home and over everything he owns. From that moment on, everything in their lives is shared.
Rabbi Yosef Bitton