Verses with the word sheshach in the Old Testament (2 verses):

Jeremiah 25:26
And all the kings of the north, far and near, one with another, and all the kingdoms of the world, which are upon the face of the earth: and the king of Sheshach shall drink after them.

Jeremiah 51:41
How is Sheshach taken! and how is the praise of the whole earth surprised! how is Babylon become an astonishment among the nations!