Eruvin 11 – Shape of a door

A shape of a door is constructed of two side posts and a bar or a rope across the top. Although it does not have practical utility, it helps for many laws. For example, an alley with an entrance wider than ten amot (20 feet) cannot be adjusted with a crossbeam on top of it, but the shape of a door here helps to permit carrying on Shabbat in such an alley. It also helps if the doors of the alley are too high for the crossbeam to be noticed.

A man from the valley of Beit Chortan took this idea to the extreme. He surrounded his field with the shapes of a door on all four sides as follows: he thrust four poles at the four corners on his field and stretched a vine across. His question now was, is that a valid separation? The matter came before the Sages, and they said that this indeed was a separation for planting. Normally, one should not plant wheat next to a vineyard. However, with the shape of a door serving as separation, it was allowed. Although the roots of the plants were next two each other and mixing, the shape of a door legally separated them into two distinct domains, and planting of wheat next the vineyard was allowed.

Resh Lakish said that just as the shape of a door was effective for planting, so too it worked for Shabbat, and the man was allowed to carry in his field. However, Rabbi Yochanan said that there was no comparison, and the laws of Shabbat were stricter. In discussing this, the Talmud considers many possibilities of how exactly his door shapes were constructed.

Art: Otto Piltz - A young Maid in a Doorway