Talmud - Eruvin 56a עירובין נ״ו א׳

coarse bread, made from coarse flour that has not been thoroughly sifted, new beer, and vegetables. This indicates that vegetables are harmful to one’s well-being. The Gemara answers: This is not difficult. This statement of Rav Huna is referring to garlic and leeks, which are beneficial; that baraita is referring to other vegetables, which are harmful. As it was taught in a baraita: Garlic is a healthy vegetable; leeks are a half-vegetable, meaning they are half as healthful. If radish has been seen, an elixir of life has been seen, as it is very beneficial to the body.

The Gemara asks: Wasn’t it taught in a different baraita: If radish has been seen, a lethal drug has been seen? The Gemara answers: This is not difficult. Here, in the baraita that deprecates radish, it is referring to its leaves; there, in the baraita that praises radish, it is referring to the roots. Alternatively, here it is referring to the summer, when radish is beneficial; there, it is referring to the winter, when it is harmful.

On the topic of the attributes of different locations, Rav Yehuda also said that Rav said: In any city that has many ascents and descents, which can be taxing to the body, people and animals die at half their days, meaning half of their life expectancy. The Gemara expresses surprise: Can it enter your mind that Rav really meant to say that they die prematurely? Even in such cities they are known to have a regular life expectancy. Rather, say: They grow old at half their days, i.e., they age prematurely due to the strain of climbing up and down the inclines. Similarly, Rav Huna, son of Rav Yehoshua, said: The ascents and descents between Beit Biri and Beit Neresh, my place of residence, made me grow old prematurely.

With regard to the measurements of a city’s boundaries, the Sages taught the following baraita: If, in order to measure the Shabbat limit, one comes to square a city, i.e., to extend the city’s boundaries to include all of its protrusions within an imaginary square, he squares it so that the sides of the square align with the four directions of the world. He sets the northern side of the square to align with the north of the world, and its southern side to align with the south of the world. And your sign by which you can recognize the directions of the world is as follows: The constellation of Ursa Major is in the north and Scorpio is in the south. The directions of the city are determined by these constellations.

Rabbi Yosei says: If one does not know how to square the city in alignment with the four directions of the world based upon the constellations, he should square it based upon the seasons, although this is less precise. How so? Where the sun rises and sets on the longest day of the year, the summer solstice, this route of the sun is the face of the north. The sun rises in the northeast and sets in the northwest, and thus travels from east to west across the north side of the world. Conversely, where the sun rises and sets on the shortest day of the year, the winter solstice, this route of the sun is the face of the south. Whereas at the vernal equinox and the autumnal equinox, when day and night are equal in length, the sun rises in the middle of the east and sets in the middle of the west.

As it is stated: “One generation passes away and another generation comes; but the earth abides forever. The sun also rises and the sun goes down, and hastens to its place, where it rises again. It goes toward the south, and turns about to the north; round and round goes the wind, and on its circuits the wind returns” (Ecclesiastes 1:4–6). The verse is understood as describing the sun’s movements, as follows: “It goes toward the south” during the day; “and turns about to the north,” on the other side of the earth, at night. “Round and round goes the wind [ruaḥ];” the word ruaḥ can also mean direction or side. Rabbi Yosei explains that these are the face of the east and the face of the west; sometimes the sun traverses them visibly, and sometimes it turns about them without being seen.

Rav Mesharshiya said: There is no validity to these rules established by Rabbi Yosei, as it was taught in a baraita: The sun has never risen, even during the summer, at the northeastern corner of the sky and set in the northwestern corner, nor has the sun ever risen, even during the winter, at the southeastern corner and set in the southwestern corner. Therefore, one can establish the directions of the world according to the sun’s path only during the autumn and spring.

On the topic of the previous discussion with regard to calculating the directions of the world based upon the seasons, Shmuel said: The vernal equinox occurs only at the beginning of one of the four quarters of a day: Either precisely at the beginning of the day, or precisely at the beginning of the night, or at midday, or at midnight.

Similarly, the summer solstice occurs only at certain times of the day: Either at the conclusion of one and a half hours or seven and a half hours of the day or night. And the autumnal equinox occurs only at certain times: Either at the conclusion of three hours or nine hours of the day or night. And the winter solstice occurs only at certain times: Either at the conclusion of four and a half hours or ten and a half hours of the day or night.

And all this is based on the principle that there are only ninety-one days and seven and a half hours between the beginning of one season and the next, as he assumed that a year is exactly 365¼ days. And similarly, each season begins precisely one-half planetary hour past the beginning of the previous season. There are seven heavenly bodies that are each ascendant for an hour at a time in a constant rotation: Mercury, Moon, Saturn, Jupiter, Mars, the Sun, and Venus. Each season begins half an hour later in this rotation than the previous season.

And Shmuel said: There is no instance when the vernal equinox occurs in the planetary hour of Jupiter and it does not break the trees with its strong winds; and there is no instance when the winter solstice occurs in the planetary hour of Jupiter and it does not dry up the seeds. And this applies only where the new moon appeared either at the hour of the Moon or at the hour of Jupiter.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Eruvin 56a discusses the health effects of garlic, leeks, and radish, plus how a city's terrain and hilly layout can hasten aging.