Smartening Up A Chump
Proverbs 26:5

Answer a fool according to his folly,
or he will be wise in his own eyes.

PCdc Commentary

You can’t cheat an honest man;
never give a sucker an even break, or smarten up a chump.
W.C. Fields, 1939, You Can’t Cheat an Honest Man

The scriptural thing to do, however, IS to smarten up that chump.
Otherwise, in his ignorance, he will continue believing that he is wise.