Matthew Poole and continuators on Jeremiah 51:64

64 And thou shalt say, Thus shall Babylon sink, and shall not rise from the evil that I will bring upon her : and they shall be weary . Thus far are the words of Jeremiah .

It hath been often said that Euphrates was that great River which ran by the Walls of Babylon; into this Seraiah is commanded by Ieremiah to throw this Roll of Prophesie against Babylon, symbolically to teach the Iews, that according to the Tenor of his Prophesie the time should come after some years, when Babylon should be destroyed never to rise again to any great view, or degree of splendor, no more than that Roll with the Stone tied to it should rise from the bottom of Euphrates.

Some read though they weary themselves, that is do what they can, or (as it is here) and they shall be weary with that weight of Judgment which shall be upon them:

Either the words of Ieremy relating to Babylon reach thus far, or all the words of Ieremiah remaining on Sacred Record (for it is thought that the next Chapter was rather penned by some other Holy Man.) Or (which seemeth the best) the Prophetical words of Ieremiah, for the matter of the next Chapter is Historical, and the book of Lamentations is not Prophetical; as to the main of it, though there be in it three or four Prophetical passages, Lam. 4.21, 22, &c.