27:2 then records that Moshe, and presumably the elders, told the people that on the day when they would cross the Jordan River, they were to set up stones, which probably had been prepared before the people crossed the Jordan River, and the stones were to be shadetam be-shid. This phrase is usually translated that the stones were to be plastered as Atler (2004, p. 1008) explains that “writing on plaster, in order to make the letters stand out more distinctly was a known procedure in the ancient Near East.” On the other hand, in a very interesting article on some words in the Tanakh that their meaning has been forgotten, David Yellin (1927, pp. 456-458) writes that the meaning of the phrase is to build a building in a strong and lasting manner, which in this case means to add mortar to the rocks. This also seems to be the explanation of the Ibn Ezra and the Bekhor Shor on 27:2. Yellen also claims that the word ketav in 27:3 means to engrave on stones, as in Shemot 32:15,16, and then the writing was not on plaster.
27:3 then records that the Torah was to be written on these stones. It is not clear how much of the Torah was to be written on these stones, see Ibn Ezra on 27:1.
27:4 then records that these stones were to be set up on Mount Eval, and the stones were to be either plastered again or mortar was supposed to be put between the stones. This verse raises several questions. Does 27:4 imply that the people were to go immediately to Mount Eval after they crossed the Jordan River? If yes, this would have been physically challenging. Mount Eval is thought to be near Shekhem which is around thirty miles from the people's crossing by the Jordan and involves going up 4,000 feet, from minus 1,000 feet by the Jordan River to 3,000 feet by the mountain. To solve this problem, the Talmud (Sotah 36a) quotes R. Shimon that the people reached Mount Eval on the day they crossed the Jordan River due to a miracle. A different possibility is the Talmud (Sotah 33b) quotes R. Eliezer that the mountains that today that we call Mount Eval is not the same ones as referred to in the Torah. 11:30 records information where Mount Eval (and Mount Gerizim) were located and maybe one can understand the verse to mean that Mount Eval and Mount Gerizim were by the Jordan River by the beginning of a road that started by the Jordan River, and went westwards reaching Elon Moreh. Yet, even if Mount Eval was near where the people were located, would there have been enough time for the people to cross the Jordan River, write on the stones, take the stones up to Mount Eval and set them up on the mountain? A third possibility is that only a select few people in excellent physical condition went to the Mount Eval, wherever it was located, on the day when the whole nation crossed the Jordan River, and then they waited sometime before the rest of the nation joined them. Yet, they would still have to have waited for the people to write on the stones before they could carry the stones up to Mount Eval. A fourth possibility is that the people crossed the Jorden River closer to Mount Eval then commonly thought, though still there would remain the difficulty of taking the stones up the mountain in one day. All of these possibilities are not convincing.
Another question is why were the stones to be set up by the Jordan River and then set up again by Mount Eval? Hizkuni notes that the word “these” in 27:4 implies that the same stones were set up in the Jordan River and on Mount Eval, but why should the same stones have been used? It would have been easier to have two sets of stones. Also, if these were the same stones, and one understands 27:2 to mean that the stones were plastered, why does 27:4 again record that the stones were to be plastered?
On the other hand, Rashi (on 27:2) and Hoffman (1961, p. 469) writes that there were two sets of stones, one by the Jordan River and one by Mount Eval? This approach seems to ignore the word “these” in 27:4.
27:5-7 then record that the people were to build an altar of stones at Mount Eval, offer sacrifices, and eat the sacrifices. This offering of sacrifices would be an example of offering sacrifices at the chosen place, 12:6,11, since G-d had chosen to have this particular ceremony at Mount Eval. Note, once this ceremony was over, then Mount Eval would not necessarily have remained a chosen place.
27:8 then records that the Torah was to be written on the stones, which might be referring to the stones that were used to build the altar, and again it is unknown how much of the Torah was to be written. Yet, if the stones in Mount Eval were the same stones as by the Jordan River, then the Torah had already been written or carved into them by the Jordan River.
My guess is that the 27:1-8 record instructions for two separate but related ceremonies. The crossing of the Jordan River was such a significant moment as the people had been waiting forty years to reach the land of Israel that it warranted a ceremony to mark the crossing. The instruction for this ceremony is recorded in 27:2,3, and this ceremony was to be done on the exact day when the people crossed the Jordan River since 27:2 records the word ba-yom. Also, the end of 27:3 indicates that the ceremony of 27:2,3 was because the people had come to the land flowing with milk and honey, as G-d had stated to Moshe by the burning bush, Shemot 3:8.
There was also a need for another ceremony to mark the covenant that Moshe was establishing with the people on the eastern side of the Jordan River, in the land of Moav, 28:69. This second ceremony is the ceremony recorded in 27:4-8. This covenant was only fully established when the tribes would go up on Mount Eval and Mount Gerizim to curse and bless the people, 11:29; 27:11-13, and then the ceremony recorded in 27:4-8, was to be prior to the tribes blessing and cursing the people. Possibly it was desired to have the ceremony for the covenant on these mountains since these mountains are thought to be near Shekhem, and Shekhem, was where Avraham had first built an altar when he entered the land of Israel, Bereshit 12:6,7. This second ceremony was similar to the ceremony in Shemot 24:3-11 by the establishment of the covenant at Mount Sinai, and since in that ceremony, the elders had a distinguished part, Shemot 24:9,10, so then here in the ceremony by the second covenant, the elders were also given a role to help Moshe inform the people of the ensuing ceremony, which parenthetically, Moshe would not participate in.
The second ceremony was not on the day when the people crossed the Jordan River, but it was sometime afterwards, for all the problems mentioned above. The basis for believing that the second ceremony was on the day when the people crossed the Jordan River is the word be-overkhem, in 27:4 (and 27:12). What does the word mean? While the word could just refer to the time it took the people to cross the Jordan River as in 27:2, this crossing can also be considered as entailing a longer process. The idea is that until the people finished establishing the covenant that was told to them in the land of Moav, they were still considered as crossing into the land of Israel. This would be similar to the idea that even when the people were in the desert they were still considered as being in the process of leaving Egypt, see 4:45,46. Note that 27:4 does not have the word on the day, which appears in 27:2, since 27:4 is referring to a period after the day when the people crossed over the Jordan River.
These two ceremonies were connected through the same set of stones. The stones were first set up by the Jordan River, then picked up and set up a second time by Mount Eval. Following the idea that mortar was put in between the stones in 27:2, this was because the stones had to stay securely in place until they were ready to be taken to Mount Eval. The stones were then re-set up on Mount Eval again with mortar in order that they would be secure for some time on Mount Eval. We can view the two ceremonies as two parts of one large ceremony.
Why did 27:8 record that the Torah was written on the stones that were set up on Mount Eval, after the Torah had already been written on the stones in 27:3, when the stones were by the Jordan River? The need to re-write the Torah might have been because the goal was to write the Torah immediately prior to the blessing and curses on Mount Eval and Mount Gerizim. Or, it could be that the writing by the Jordan River was rushed and then not so clear, while the writing on Mount Eval could have been slower and clearer. Note that 27:8 ends with the phrase that this writing of the Torah was to be very clear (see Ibn Ezra on 27:8), which could be to be emphasize that this second writing was to be clearer than the first writing by the Jordan River. Finally, there is the possibility that during the time from the crossing of the Jordan River until the second ceremony on Mount Eval some of the words on the stones had already started to be blurred, and hence there was a new writing for the second ceremony.
Bibliography:
Alter, Robert, 2004, The five books of Moses: A translation and commentary, New York: W. W. Norton and Company
Hoffmann, David Tzvi (1843-1921), 1961, Commentary on Deuteronomy, translated by Tzvi Har-Shefer, Tel Aviv: Nezach.
Yellin, David, 1927, Forgotten meanings of Hebrew roots in the Bible, in Jewish Studies in Memory of Israel Abrahams, New York: The Alexander Kohut Memorial Foundation, Press of the Jewish Institute of Religion, pp. 441-458.