# Prepare your slaughter for his children

"Get ready to kill the children of the king of Babylon" 

# for the iniquity of their ancestors

"because their forefathers have sinned greatly" 

# so they will not rise up

"so they will not become powerful" or "so they will not attack"

# possess the earth

"take control of the peoples on the earth" or "conquer the peoples on the earth" 

# fill the whole world with cities

"build cities all over the world"