Stones In Water
There are places were stones are related to river water. These 2 symbols combine in these stories, suggesting text on stone can be drawn out of water.
Crossing the Jordan
When the children of Jacob crossed the Jordan into Canaan the were told to take 12 stones up out of the river. They did so and piled them up where they were staying.
These appear to have been setup as a monument to the crossing of the river itself. Curiously, though, the text is unclear as to the exact meaning of this story.
If we apply the general meaning of stones, as carriers of inspired text, and the river as the liver of life, or human cells. Then this story has interesting meaning.
The authority to cross into the promised land is based on the possession of the text that is vaulted inside the human genome. More of that text had been revealed to Moses across the previous 40 years.
It also means that should that text be ignored that the children of Jacob would leave the promised land, just as Jacob's family had done centuries before.
Jeremiah's Stone Into River
Jeremiah wrote a letter to the exiles in Babylon. They were told it would be 70 years there. So they needed to settle down, raise family and so on because nothing they could individually do would stop Joshua's planned timeline.
That year length shows up prophetically again in Daniel and is used to time the events of the New Testament. It is also used in a discussion between Joshua and Peter and times our time now in world history. Keep these in mind as we see what Jeremiah said to do with that letter.
Stones, of course, are units of writing. Like the stones carved at Ebal and Gerizim. The river is the larger body of writing, potentially huge. Only certain parts of that writing matter to salvation.
As always, no prophetic writing is interpreted in its own book. So the additions are evident here. This is not about Babel sinking into a river. We must use other writing to interpret the stone in the river.
Jeremiah's letter becomes a stone in the river. Left there for such a time as it can be symbolically lifted out.
At all previous times the content of the stone is given by revelation to various writers. This was even true up through the new Testament era.
The final timing for these 70 years is 70 Jubilees from the Exodus, or our century. We now have the basic tech to read the genome directly. Now we have the text to lift the stone from the river.