en_tn/ezr/04/14.md

eaten the palace salt

This is a figure of speech describing the support they get from the palace. (See: rc://en/ta/man/translate/figs-idiom)

there will be nothing remaining for you beyond the Great River

"There will be no taxes for you to collect beyond the Euphrates river." These men are seeking to incite the King against the Jews by exaggerating the impact one small rebuilt town would have on their tax revenue. (See rc://en/ta/man/translate/figs-hyperbole)