John Gill Commentary Proverbs 26:4

"Answer not a fool according to his folly, Lest thou also be like unto him." — Proverbs 26:4 (ASV)

Answer not a fool according to his folly Sometimes a fool, or wicked man, is not to be answered at all; as the ministers of Hezekiah answered not a word to Rabshakeh; nor Jeremiah the prophet to Hananiah; nor Christ to the Scribes and Pharisees; and when an answer is returned, it should not be in his foolish way and manner, rendering evil for evil, and railing for railing, in the same virulent, lying, calumniating, and reproachful language;

lest you also be like to him ; lest you also, who are a man of understanding and sense, and have passed for one among men, come under the same imputation, and be reckoned a fool like him.