Matthew Henry Commentary Proverbs 24:7-9

"Wisdom is too high for a fool: He openeth not his mouth in the gate. He that deviseth to do evil, Men shall call him a mischief-maker. The thought of foolishness is sin; And the scoffer is an abomination to men." — Proverbs 24:7-9 (ASV)

A weak man thinks wisdom is too high for him, therefore he will make no effort for it. It is bad to do evil, but worse to devise it. Even the first stirrings of sin in the heart are sin, and must be repented of. Those who strive to make others hateful, make themselves so.