“He who is devoid of wisdom (“lacks heart”—literally) despises his neighbor, but a man of understanding holds his peace” (Prov. 11:12).
Envy and arrogance are such ugly, senseless, and heartless sins. They require no talent, discernment, or self-control. Despising one’s neighbor because of envy or because of pride betrays a head that bankrupt of wisdom.
Because “it is better to be thought a fool than to open your mouth and remove all doubt”, the only thing more empty-headed than despising a neighbor is opening your mouth and letting everyone know you have an ugly and senseless heart.