He that walketh with wise men shall be wise: but a companion of fools shall be destroyed.
He that walketh (namely, continuously and habitually) with wise men shall be wise. So the Masoretic text reads х howleek (H1980) ... yechªkaam (H2449)]. But the Kethibh, or Hebrew text, reads imperatively, 'Walk ... be wise' [haalowk ... yechªkaam, the infinitive absolute, for the imperative].
But a companion of fools shall be destroyed. 'But one associating himself with and taking pleasure in х ro`eh (H7462)] fools.' Compare Proverbs 28:7, margin (the literal meaning of the Hebrew verb raa`ah (H7462), from which "companion" comes, is to feed; boon-companions, who feed together); Proverbs 29:3. "Destroyed" - literally, 'shall be made evil,' and so 'shall be punished with evil.' There is a play upon like Hebrew sounds in "companion" and "destroyed," ro`eh and roa`. The Greek Theognis says, 'Thou shalt learn good from the good; but if thou associate with the bad, thou shalt lose even the mind thou hast' [esthloon men gar ap' esthla matheeseai een de kakoisi Summichthees, apoleis kai ton eonta noon]. Seneca says, 'The road is long by precept; it is short and effectual by example.' What one sees make more lasting impression than what one hears. As bad air injures the strongest health, so association with the bad hurts the best mind.