"Don’t say, “I will pay back evil.”" (20:22). Does that mean a wrong doesn't matter?

The verse doesn't stop at Don't. It goes on: "Wait for the LORD, and he will save you" (20:22) (tap Wait). And the same chapter takes wrong seriously: "A king who sits on the throne of judgment scatters away all evil with his eyes" (20:8), and "The LORD detests differing weights, and dishonest scales are not pleasing" (20:23). What 20:22 turns away is saying I will pay back. In Hebrew I will pay back is from shalam, and Proverbs uses the same verb of what the LORD does: "He who has pity on the poor lends to the LORD; he will reward him" (Proverbs 19:17), and "the LORD will reward you" (Proverbs 25:22) (tap pay back). Another saying opens with the same Don’t say: "Don’t say, “I will do to him as he has done to me; I will repay the man according to his work.”" (Proverbs 24:29); its repay is another Hebrew verb. Paul (Romans 1:1) wrote, "Repay no one evil for evil" (Romans 12:17), and "Don’t seek revenge yourselves, beloved, but give place to God’s wrath" (Romans 12:19); he doesn't cite Proverbs. The notes on Exodus 21 look at Jesus's words in Matthew 5:38-39. These notes don't apply 20:22 to any wrong anyone has suffered today, or say what anyone should do about one.