A common misconception about the eruv is that it is merely an enclosure around a space: walls, beams, or even strings tied to poles. In fact, for the rabbis of the Talmud, the eruv’s effectiveness for allowing objects to be carried on Shabbat depends on the space within the eruv as much as on the eruv itself.
On today’s daf, the rabbis are discussing an outdoor space that is enclosed by a fence. Given what we’ve learned so far in Tractate Eruvin, we would assume it is permitted to carry on Shabbat in a space that is entirely surrounded. But according to the mishnah on today’s page, that is not the case:
Rabbi Yehuda ben Bava said: With regard to a garden or a karpef, an enclosed courtyard used for storage, that is not more than seventy cubits and a remainder, and is surrounded by a wall ten handbreadths high, one may carry inside it, as it constitutes a proper private domain. This is provided that it contains a watchman’s booth or a dwelling place, or it is near the town in which its owner lives, so that he uses it and it is treated like a dwelling.
According to Rabbi Yehuda ben Bava, carrying in an enclosed area is allowed only if it contains a watchman’s booth or a dwelling place, or it is close to a city. But another rabbi, also named Yehuda, disagrees, saying that even having a water cistern, a ditch, or a cave inside the space would be sufficient to allow carrying. The rabbis disagree about the specifics, but they agree on the larger point: carrying is only permitted in an enclosed space if it resembles a living space. Their disagreement is only about what defines a space as a living space, whether a resource like water, or the protection of a watchman, or even just a convenient location.
Rabbi Akiva and other rabbis maintain that none of this is necessary. According to them, all that matters in determining whether an enclosed space is suitable for carrying on Shabbat is its size. But in determining what that size is, they too look to a standard that suggests the idea of a living space: The courtyard surrounding the Tabernacle, which measured about 5,000 square cubits. So long as the enclosed space is no larger than this, one can carry within it on Shabbat with no further modifications.
Why did the rabbis consider the Tabernacle a model for an eruv? The Tabernacle was a portable sanctuary that the Israelites carried with them as they wandered in the wilderness. Along with the permanent version built later, the Temple in Jerusalem, the Tabernacle is described in the Torah as a place where God dwells. Even the Hebrew words we use to describe these holy sites remind us of our homes: the Tabernacle is a mishkan, meaning dwelling place, and the Temple Mount is Har Habayit, literally “the mount of the house.”
God’s dwelling place thus becomes a model for our dwellings. This parallel occurs throughout the Talmud. We’ve already seen it multiple times already in Eruvin, in the debate about how large an area a caravan is permitted to enclose on Shabbat and in the debate about the structural elements that constitute an entrance. In Tractate Sukkah, the size of a sukkah is based on the size of the Holy of Holies that lay at the innermost point of the Tabernacle. And in Tractate Bava Batra, the height of a wall between neighboring properties is compared to the height of the Temple’s walls.
For the rabbis, God’s presence is immanent — not just up in heaven, but also here on earth. God’s home is just another home in the neighborhood, and its descriptions teach us what our homes and courtyards are to look like. We can see this as an established fact, but also as a challenge: How can we turn our homes, and even our outdoor spaces, into sacred spaces where God dwells?