Wealth blunts, poverty sharpens, the critical power of intellect.

The rich man [is] wise in his own conceit; but the poor man that hath understanding searcheth (e) him out.
(e) And judge that he is not wise.

The rich man is wise in his own conceit,.... Ascribing his getting riches to his great sagacity, wisdom, and prudence; and being flattered with it by dependents on him;
but the poor that hath understanding searcheth him out: a man of good understanding, whether in things natural, civil, moral, or spiritual, though poor, as a man may be poor and yet a wise man; such an one, when he comes into company with a rich man, wise in his own conceit, he soon by conversation with him finds him out to be a very foolish man, and exposes him as one; for riches are not always to men of understanding, or all that have them are not such; and better is a poor wise man than even a foolish king; see Ecclesiastes 9:11.

Rich men are so flattered, that they think themselves superior to others.

A poor but wise man can discover (and expose) the rich and self-conceited.

11 A rich man deems himself wise;
But a poor man that hath understanding searcheth him out,
or, as we have translated, Proverbs 18:17, goes to the bottom of him, whereby is probably thought of the case that he seeks to use him as a means to an ignoble end. The rich man appears in his own eyes to be a wise man, i.e., in his self-delusion he thinks that he is so; but if he has anything to do with a poor man who has intelligence, then he is seen through by him. Wisdom is a gift not depending on any earthly possession.