Jewish tradition teaches that all of humanity is connected to God, as God created the first human. Similarly, all of humanity is connected to one another, since we all stem from the first human being. In fact, the Midrash teaches that this was intentional, so no one could say to another person, “My father was greater than yours.”
Eruvin 34 is also all about connections. The daf opens with the rabbis continuing their discussion from the previous page about how high off the ground an eruv can be. As we’ve seen, an eruv in general can be placed as high as ten handbreadths from the ground. Anything higher and the connection is lost.
Later, the rabbis discuss the case where an eruv is placed in a pit in the public domain and the person who placed it there is in a karmelit, that intermediary space that is neither public nor private. As we saw yesterday, the rabbinic laws of Shabbat don’t apply at twilight. And since carrying between a public area and a karmelit is only a rabbinic prohibition, and since the rabbis believed it was essential that the person be able to access their eruv, an eruv of this type is permitted. The connection between the person and the eruv is a valid one.
Finally, we come to a mishnah that teaches this law:
If one put the eruv in a cupboard and locked it, and the key was lost, so that he is now unable to open the cupboard and access the eruv, it is nonetheless a valid eruv. Rabbi Eliezer says: If he does not know that the key is in its place, it is not a valid eruv.
According to the mishnah, if one is cut off from their eruv on Shabbat because it is locked in a cupboard to which the key has been lost, it remains a valid eruv. But Rabbi Eliezer disagrees. If the whereabouts of the key are unknown, the eruv is not a valid eruv.
The rabbis go on to debate the particulars of this case, and the Gemara records an opinion suggesting that the critical issue is where the key has been lost. If the key was lost in a city, the eruv remains valid. But if it was lost in a field, it doesn’t. The idea here is that if the key is lost in a city, one could still theoretically be able to bring the key to the cupboard by means of courtyards that have been joined together and within which it is permitted to carry. But in a field, that would be impossible, as it’s forbidden to carry an object in an open field on Shabbat. In the latter situation, the connection between the key and the cupboard holding the eruv has been broken.
In a sense, this is the rabbinic version of WiFi. The eruv is tethered to the person who placed it by an invisible connection. Stray too far, and the connection is lost. So it is with an eruv that is placed too high or too low, and so it is with people and God. We must maintain proximity to establish connection.