Matthew Poole and continuators on Jeremiah 51:41

41 How is Sheshach taken? and how is the praise of the whole earth surprized ? how is Babylon become an astonishment among the nations ?

We meet with this term Sheshach only here, and chapter 25.26. both places leave it doubtful whether it be to be taken for an Idol which they called by the name of Shach: or a name given to the City of Babylon which worshipped that Idol, to the honour of which the Babylonians kept a yearly Festival for several dayes. In the time of which Festival they say it was that Cyrus took the City of Babylon.

Babylon that was so famous over all the World for her splendor.

And so it is interpreted in the next words, wherein Babylon for the punishment brought upon it is said to be an astonishment to all Nations, which makes it probable that Babylon is what was called Sheshach, by the doubling of a letter, because she worshipped Schach.