Quick answer
Paying attention to a poor person's legal case is treated as a form of knowledge. The verse says the wicked lack it.
Read both lines
דִּין דַּלִּים is the legal claim of the poor, a court term, so this is not general sympathy. The righteous man knows the case, which means he has looked into a matter that does not concern him and could not benefit him. The verb is knows.
Then the second line makes the failure cognitive rather than moral, exactly as 28:5 did when it said evil men do not understand justice. Two chapters, the same claim: this is a thing some people cannot see, not a duty they are declining. That is worth holding onto, because it explains why arguing about it so often fails and where the book locates the actual problem. It also belongs to the poverty-and-injustice thread whose home entry is 13:23.
Related: Proverbs 28:5 · Proverbs 13:23 · Proverbs 31:8–9 · Proverbs 22:22–23
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.