How do opponents of Penal Substitution explain God's declaration that He "will not leave the guilty unpunished"?

In referring to opponents of Penal Substitution theory , I'm referring specifically to those who view it as a ***false*** view of the Atonement, not merely that it is incomplete (*eg* those who hold to alternative theories of Atonement may assert their theories are more holistic, but will not necessarily deny that penal substitution is a contributing element within them). Consider: > ... the Lord will not leave the guilty unpunished. - Nahum 1:3b NIV > Acquitting the guilty and condemning the innocent— the Lord detests them both. - <a href="/redirect?url=https%3A%2F%2Fwww.biblegateway.com%2Fpassage%2F%3Fsearch%3Dprov%252017%253A15%26version%3DNIV" class="external-link" target="_blank" rel="nofollow noopener">Proverbs 17:15 NIV <i class="fas fa-external-link-alt fa-xs"></i></a> > Have nothing to do with a false charge and do not put an innocent or honest person to death, for I will not acquit the guilty. - Exodus 23:7 NIV If Christ doesn't bear the penalty or punishment for our sins by taking our guilt upon himself, where does the condemnation and punishment go? What is the specific mechanism by which, a sinner can be saved from their sins without making nonsense or lies of the preceding declarations?