Eruvin 32 - One's dwelling on Shabbat
One Shabbat, one has to "stay in his place." This means that he must imagine a circle around his dwelling, with the radius of two thousand amot (about half a mile) and never walk beyond the limit of this circle. A city is considered one's dwelling, so practically one can walk half a mile away from the city, but no more than that.
If he still needs to go further, he can change his dwelling place. For that, on Friday he can walk up to two thousand amot in the direction that he will have to go on Shabbat, and place food ("eruv") there. This place then becomes his new "dwelling," and he has to stay in the new circle. We thus find that he can go from his home to the new place, but not in the opposite direction, because this is where his new circle ends.
If he cannot go there on Friday to establish his eruv, he can send a messenger. However, if this messenger is a deaf-mute or deranged person, his eruv won't be valid, because they do not have the necessary understanding of the matter. On the other hand, if the deranged person only transports his eruv, but a sound-minded person accepts it there, it is valid.
Art: Jacobus Vrel - Street Scene with Two Figures Walking Away
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