What does Proverbs 26:4 mean?

This half of a two-part lesson (Proverbs 26:5) uses the phrase "according to" to mean "in the manner of." It's unwise to imitate a foolish person's attitude, mannerisms, or approach. A related modern English proverb advises, "don't wrestle with pigs, since you only get dirty and the pig enjoys it." In the book of Proverbs, "foolishness" means rejection of God and His truth (Proverbs 1:7). Insults, lies, tricks, anger, pettiness, and other things are foolish and should not be imitated. Being dragged down to that level is neither sensible, nor godly.

Jesus answered many questions, sometimes reflecting the style of the one asking (Matthew 12:1–8; 19:21; John 3:10; 4:16). However, Jesus did not respond to petty insults with insults, or to lies with lies. When His critics were unfair or unkind, Jesus could be firm—even forceful (John 9:40–41; Matthew 22:18). Yet He did not use the same foolish tactics as those who attacked Him. Nor did He bother to answer when the question, itself, was insincere. When Herod tried to coerce Jesus into performing a miracle Jesus refused to respond at all (Luke 23:8–9). Herod didn't need a sign to prove Jesus was the Son of God. His questioning was shallow and mocking.

Verses 4 and 5 seem like contradictory statements. And, in fact, they do suggest opposite actions. However, the context of each is subtly different; the intended lesson is about when to speak and when to remain silent. In fact, it's possible to think of them as two halves of a single proverb. This pair of statements provides an excellent example of Scripture presenting tension between two extremes. Careless reading—especially out of context—can interpret these as contradictions. Here, of course, the phrases are written together, making their intended meaning easier to untangle.

Another way to distinguish verses 4 and 5 is noting that there is a difference between giving an answer "to" foolishness, as opposed to giving an answer "in" foolishness. To correct something using wisdom is good; to imitate something unwise is not.