After reading Jeremiah's scroll in Babylon, what was Seraiah to do with it?

Answer: Sink it in the Euphrates

Seraiah was to tie a stone to the scroll and throw it into the Euphrates, saying, "In the same way Babylon will sink and never rise again."

“When you finish reading this scroll, tie a stone to it and cast it into the Euphrates.”— Jeremiah 51:63 (BSB)