en_tn/rom/03/19.md

whatever the Law says, it speaks to

"everything that the Law says people should do is for" or "all the commands that Moses wrote in the Law are for" (See: rc://en/ta/man/translate/figs-personification)

in order that every mouth may be closed

AT: "so that no people will be able to say anything valid to defend themselves" (See: rc://en/ta/man/translate/figs-synecdoche; See: rc://en/ta/man/translate/figs-activepassive)

flesh

Here it means in a figurative way to refer to all human beings or all living creatures.

For

Possible meanings are 1) "Therefore" or 2) "This is because" or 3) "Instead."

through the Law comes the knowledge of sin

AT: "when someone knows God's law, he realizes that he is not righteous but rather sinful before God"