RobH_en_tn/jer/51/44.md

I will punish Bel

Bel was the main god of the Babylonians and represents the whole country and the people that worshiped it. (See: rc://en/ta/man/translate/figs-metonymy)

out from his mouth what he swallowed

Yahweh compares all the sacrifices and offerings to Bel to things he ate. (See: rc://en/ta/man/translate/figs-personification)

the nations will no longer flow

The many nations that come to Babylon to sacrifice to Bel is spoken of as a river that moves along. Alternate translation: "the people of other nations will no longer come in large groups" (See: rc://en/ta/man/translate/figs-metaphor)