Tractate Berakhot of the Talmud of Eret—-Israel: 0012

1:
This rather long and recondite passage is only a part of this present discussion, the remainder of which will be dealt with in our next shiur. This passage is pure aggadah. That is to say it is not halakhic. It is, in fact, a presentation of rabbinic cosmology followed by an exposition on the geography of the Garden of Eden.

2:
In order to understand this passage it is perhaps useful to give a brief resumי of what seems to me to be a typical understanding the sages had of the nature of the cosmos.

The sages imagined the cosmos to be geocentric. That is to say that the cosmos consists of a flat Earth above which is the sky and below which is the abyss ("the waters which are under the Earth"). The sky is like a convex sphere above the Earth. Imagine the flat earth as a serving platter and the sky above it as a domed lid. The sky has two extremities, to the east and to the west. Every day the sun rises in the east, travels across the sky in a westerly direction, sets in the west, and then travels back to the east during the night underneath the abyss. We cannot see the sun during the night because it is travelling beneath the Earth, under the abyss. At the eastern and western extremities of the sky is an area called the 'density of the sky', a fuzzy area in which the light from the sun can be partially seen as it passes through. It seems that they saw the sky as being particularly dense at its eastern and western extremities, thus obscuring much of the sun's light. Above the visible sky are other skies, or firmaments, seven in all. In each of these firmaments is located one of the visible celestial phenomena: the moon, the sun, the moveable stars (i.e. planets) and the fixed stars. Above them all is the domain of the divine.

3:
You will recall that in 0010 we learned the view of Rabbi Ḥatzna that "from first light until daylight a person can walk four miles; from daylight until sunrise another four miles". Now the Gemara notes that it seems that in this Rabbi Ḥatzna agrees with Rabbi Ḥiyya, who is following the opinion of Rabbi Yehudah. Actually, this is a deduction. What Rabbi Yehudah in fact said was:

For the meaning of 'density of the sky' see the cosmology above. It is not at all clear what kind of definition Rabbi Yehudah is trying to give here: is it the breadth of the 'density of the sky'? Is it its depth? Presumably what he means to say is that it would take a human being fifty years to traverse 'the density of the sky' on foot. But the sun runs at a different velocity. During the time that it takes for the sun to traverse the 'density of the sky' at its eastern or western extremes, on Earth a man could walk four kilometers. Since it is a known fact that a person can walk 40 kilometers in a day it follows that the time it takes the sun to traverse the 'density of the sky' is one tenth of the day.

4:
We are also told that it would take a human being (walking 40 kilometers each day) fifty years to traverse the depth of the Earth and a further fifty years to traverse the abyss which is beneath the Earth. These cosmological facts are supported by three biblical verses. In Isaiah 40:22 God is described as "sitting on the circle of the Earth"; Job 22:14 states that the "circle of the heavens goes"; and Proverbs 8:27 speaks of God setting "the circle of heaven upon the abyss". Thus we have three heavenly circles: Earth, heaven and abyss — in that order.

5:
The Gemara now turns to a different topic: an exposition of the Garden of Eden. The tree of Life, which was in the middle of the Garden, had a trunk which was 500 years wide! (In other words, it would take a human being — walking at 40 kilometers a day — 500 years to walk around it.) In addition "all the waters of creation dispersed from under it". This is supported by quoting Psalm 1:3

6:
We are further told that "the tree of life was one sixtieth of the garden and the garden was one sixtieth of Eden." The accepted English title 'Garden of Eden' is a misnomer. The bible [Genesis 2:8] describe a garden in Eden. Thus there was an area called Eden, within which was a garden, within which was the tree of life.

7:
"And a river went out from Eden to water the garden" [Genesis 2:10]. This river divided into four separate rivers. Genesis 2:10-14 describes their geographical setting. Apparently it was understood that one of these rivers was the Nile which flows through Egypt. But Egypt, for all the extraordinary length of the Nile, is infinitely smaller than Ethiopia. (When reading this I could not help but think that there was, perhaps, here an attempt to define the size of the continent of Africa.

8:
Twice a day, every day, we recite the Shema. The concluding words of the second paragraph of the Shema are "as long as the heavens are above the Earth" [Deuteronomy 11:21]. The sages interpret this as saying that something is "as many as the years that heaven is above Earth". That 'something' is the total number of years lived by the three patriarchs, Abraham, Isaac and Jabob. Abraham lived 175 years; but we must deduct three years for the first three years of his life when he was yet ignorant of God's existence. So for Abraham we have 172 years; for Isaac 180 years, and for Jacob 148 years, making a total of 500 years. Thus 'the heavens are above the Earth' a distance which would take a human being 500 years to traverse (covering 40 kilometers each day).

9:
It would perhaps be useful at this stage to recap what we have learned about the the way the sages understood the 24-hour day:

It consists of four periods:

1. The sun travels through the 'density of the sky' in the east; its light gradually increases as it passes through and out of this area; this period is from dawn until sunrise, and it lasts about the time it takes a man to walk 4 kilometers.
2. The sun exits the 'density of the sky'; this moment is sunrise; the sun now travels across the sky throughout the day.
3. The sun enters the 'density of the sky' at its western point (sunset) and its light begins to dim; this period is called twilight, and it lasts about the time it takes a man to walk 4 kilometers.
4. The sun travels beneath the abyss and this period is night. At the end of night the sun once again reaches the eastern 'density of the sky' and the process repeats itself.