John Gill, on Jer 51:61

“And Jeremias said to Saraias: When thou shalt come into Babylon, and shalt see, and shalt read all these words,”

“And it shall be, when thou hast made an end of reading this book,.... To the captive Jews; and having also said the above words by way of prayer and approbation: that thou shalt bind a stone to it, and cast it into the midst of Euphrates; a river by which Babylon was situated. The book, being read, was to be rolled up again, and then a stone tied to it, and cast into the middle of the river, where the waters were deepest, and from whence it could not be taken up; and this was a sign confirming the above prophecy; compare with this what was done by a mighty angel concerning mystical Babylon, in which there is an allusion to this, Rev 18:21.”

Imported from an open dataset — not yet checked against the printed edition.