Albert Barnes Commentary Zechariah 8:16

"These are the things that ye shall do: speak ye every man the truth with his neighbor; execute the judgment of truth and peace in your gates;" — Zechariah 8:16 (ASV)

These are the things that you shall do - He exhorts them to the same duties to which the former prophets had exhorted their fathers (Zechariah 7:9–10): first, positively, to truth and peace; then, to avoid everything contrary to it.

“Judgment of peace” must be judgment that issues in peace, as all righteous judgment, when righteously received (a situation in which each party acquiesces), necessarily does.

Kimchi comments: “If you judge righteousness, there will be peace between the litigants, according to that proverb (Sanhedrin folio 7a, quoted by McCaul, page 78), ‘He that has his coat taken from him by the tribunal, let him sing and go his way’ (because,” says a gloss by Rashi, quoted there, “they have judged the judgment of truth, and have taken away that which would have been stolen property if he retained it,” it being in fact not his).

And they have quoted that, And all this people shall go to their place in peace (Exodus 18:23). This phrase, “all this people,” includes even the one who is condemned in judgment.

It is also interpreted as arbitration. “What sort of judgment is that, in which there is peace? It is that of arbitration.”