First of all, for Exodus15:8 please check up various other translations. You easily discover that נד as in Exodus15:8 is translated as "heap" or as "hill". This is the most common translation, and not "wall". See for instance ASV, AKJV, JPS Tanakh, ESV, etc.
And this is different from Exodus14:22, where we read חומה , which is indeed "a wall".
Now let's return to נד. We also find this in:
And when the soles of the feet of the priests bearing the
ark of the LORD, the Lord of all the earth, shall rest in the waters
of the Jordan, the waters of the Jordan shall be cut off from flowing,
and the waters coming down from above shall stand in one heap. (ESV)
This is about the Jordan River which stopped flowing opposite Jericho, when the Israelites crossed over following Joshua.
Another interesting place:
He gathers the waters of the sea as a heap; he puts the
deeps in storehouses. (ESV)
This is a Psalm of praise, referring to the power of God made manifest during creation and during the crossing of the Red Sea and using the same word in both cases.
And somewehere else in the Psalms, referring specifically to Genesis 15:8:
He divided the sea and let them pass through it, and made
the waters stand like a heap.(ESV)
All of these fragments are describing a miracle of divine control of the Lord over His creation.
Now, as dictionaries let us know, נד means something piled up on itself (see Strong's Hebrew #5067. See also W. Baker, The complete word study dictionary : Old Testament. Chattanooga, TN: AMG Publishers, 2003)
This, I think, describes very well the image that the author is intending to convey.
In addition to these, there is something that you may find useful, that I am quoting just as it is from the JPS Torah Commentary for Exodus15:8:
"The waters are positioned in three stages:
the blast of Your nostrils. Similar poetic imagery for the wind is found in 2 Samuel 22:16.30
piled up. An ancient tradition, preserved in Targum Onkelos and the Mekhilta,(MdRY Beshallaḥ, Shirta 6, p. 137, Ibn Ezra, Lek. Tov; so
Malbim) construes the unique Hebrew neʿermu as though deriving not
from ʿaremah, “a heap, pile,”(Cf. Jer. 50:26; Hag. 2:18; Song 7:3;
Ruth 3:7; Neh. 13:15 (cf. 3:34); 2 Chron. 31:6, 9) but from ʿormah,
“cunning, shrewdness.”(Cf. Exod. 21:14; Josh. 9:4; Prov. 1:4; 8:5,
12) This is taken as an allusion to retributive justice. The Egyptians
“dealt shrewdly” with the Israelites, a policy that led to the decree
to drown the Israelite males; now the waters deal with equal
shrewdness in drowning the oppressors.(Exod. 1:10, 22, although a
different verb is used there; but cf. Prov. 8:12.)
like a wall. Literally, “like a mound [of earth].” (Cf. Josh. 3:13, 16; Pss. 33:7; 78:13)
froze. They coagulated and formed a solid mass.(Cf. Job 10:10)"
[Sarna, N. M. (1991). Exodus. English and Hebrew; commentary in English. The JPS Torah commentary, Philadelphia: Jewish Publication Society, p. 78]
At your request I am expanding the JPS Torah Commentary for Exodus15:8 so as in a brief synopsis. I made some interventions in the original text taken from the JPS Torah Commentary. This is why I decided to keep the quote above just as it is to have it as a reference and in the hope that perhaps it would work out for you as a synthesis to guide you throughout this maze:
"The waters are positioned in three stages:
the blast of Your nostrils. Similar poetic imagery for the wind is found in 2 Samuel 22:16.
2 Samuel 22:16
Then the channels of the sea were seen; the foundations of the world
were laid bare, at the rebuke of the LORD, at the blast of the breath
of his nostrils.(ESV)
piled up. An ancient tradition, preserved in Targum Onkelos and the Mekhilta,(MdRY Beshallaḥ, Shirta 6, p. 137, Ibn Ezra, Lek. Tov; so Malbim) construes the unique Hebrew neʿermu as though deriving not from ʿaremah, “a heap, pile” but from ʿormah, “cunning, shrewdness”.
Here, Mekhilta De-Rabbi Ishmael, Tractate Shirata, VI goes as follows:
- A. "At the blast of your nostrils the waters piled up:" B. With the measure with which they meted out to others was their measure
meted out to them: C. They had said, "Come, let us deal wisely with
them" (Ex. 1:10). D. So you for your part made the water shrewd, so
that the water made war against them and carried out a variety of
punishments against them: C. "At the blast of your nostrils the
waters became tricky." Justice means, with the measure with which they
meted out to others was their measure meted out to them. The entire
Song is made into an exercise in the realization of God's rule through
[I quote this from Jacob Neusner, A Theological Commentary to the Midrash, vol. 9. Mekhilta attributed to Rabbi Ishmael, University Press of America, 2001, p. 92]
Now the biblical verses:
- neʿermu deriving from ʿaremah, “a heap, pile,”
Come against her from every quarter; open her granaries; pile her up
like heaps [עֲרֵמִ֖ים] of grain, and devote her to destruction ....
Your breasts are like two fawns, twin fawns of a gazelle. (ESV)
שְׁנֵ֥י שָׁדַ֛יִךְ כִּשְׁנֵ֥י עֳפָרִ֖ים תָּאֳמֵ֥י צְבִיָּֽה׃ (WLC)
And when Boaz had eaten and drunk, and his heart was merry, he went to
lie down at the end of the heap of grain [הָעֲרֵמָ֑ה]. (ESV)
Neh. 13:15 (cf. 3:34)
In those days I saw in Judah people treading winepresses on the
Sabbath, and bringing in heaps of grain [הָעֲרֵמ֣וֹת] and loading them
on donkeys, and also wine, grapes, figs, and all kinds of loads, which
they brought into Jerusalem on the Sabbath day. And I warned them on
the day when they sold food. (ESV)
2 Chron. 31:6, 9
And the people of Israel and Judah who lived in the cities of Judah
also brought in the tithe of cattle and sheep, and the tithe of the
dedicated things that had been dedicated to the LORD their God, and
laid them in heaps [עֲרֵמ֥וֹת]. (ESV)
2. neʿermu as though deriving from ʿormah, “cunning, shrewdness.”
But if a man willfully attacks another to kill him by cunning
[בְעָרְמָ֑ה], you shall take him from my altar, that he may die.(ESV)
... they on their part acted with cunning [בְּעָרְמָ֔ה] and went and
made ready provisions and took worn-out sacks for their donkeys, and
wineskins, worn-out and torn and mended, ...(ESV)
... to give prudence [עָרְמָ֑ה] to the simple, knowledge and
discretion to the youth (ESV)
Prov. 8:5, 12
O simple ones, learn prudence [עָרְמָ֑ה]; O fools, learn sense.
This is taken as an allusion to retributive justice. The Egyptians “dealt shrewdly” with the Israelites, a policy that led to the decree to drown the Israelite males; now the waters deal with equal shrewdness in drowning the oppressors.(Exod. 1:10, 22, although a different verb is used there; but cf. Prov. 8:12.) Just as in Mekhilta De-Rabbi Ishmael, Tractate Shirata, VI as seen above:
Exodus 1:10, 22
Come, let us deal shrewdly [נִֽתְחַכְּמָ֖ה] with them ...[...] Then
Pharaoh commanded all his people, “Every son that is born to the
Hebrews you shall cast into the Nile, but you shall let every daughter
CF Prov 8:12
I, wisdom, dwell with prudence, and I find knowledge and discretion.(ESV)
אֲֽנִי־חָ֭כְמָה שָׁכַ֣נְתִּי עָרְמָ֑ה וְדַ֖עַת מְזִמֹּ֣ות אֶמְצָֽא׃ (WLC)
like a wall. Literally, “like a mound [of earth].” (Cf. Josh. 3:13, 16; Ps. 33:7; Ps. 78:13 /// please find those listed above in my reply.
froze. They coagulated and formed a solid mass.(Cf. ....
Did you not pour me out like milk and curdle me [תַּקְפִּיאֵֽנִי] like
So, there is most likely that Exodus15:8 is describing a miraculous event, first of all. As about what did the author have in mind and how he understood this event ... who can tell? On the other hand, yes, it seems that there is a non-literal way of understanding the heap of water, if you follow the suggestions found in the JPS Torah Commentary. Sorry I haven't got enough time to do it now myself, I'd really love to do it.
I would suggest some further reading on this very interesting topic:
Jonathan Kaplan, My Perfect One: Typology and Early Rabbinic Interpretation of Song of Songs, Oxford University Press, 2015, pp. 50, 59-60