Proverbs 28:16

The prince that wanteth understanding is also a great oppressor: but he that hateth covetousness shall prolong his days.
– Proverbs 28:16

A prince is a ruler and wanting understanding means he is a foolish ruler. He lacks the wisdom needed in ruling justly. The foolish ruler becomes an oppressor, or tyrannical in his rule. The word for oppressor refers to extortion. The second line forms an uneven parallel. The ruler that hates covetousness has wisdom and it tends to life (Proverbs 15:28; 29:14). The word for covetousness refers to unjust gain that might result from deceptive business practices, or in this case, tyrannical abuse of authority. The implication for the foolish ruler is their folly rejects wisdom and tends to death (Proverbs 8:36).

Proverbs 28:15

As a roaring lion, and a ranging bear; so is a wicked ruler over the poor people.
– Proverbs 28:15

The sayings in verses 15-16 continue the theme of wisdom to rulers. The saying compares a wicked ruler to a roaring lion and a ranging bear. Wild and predatory animals provide descriptive analogies for various foolish human behaviors (Proverbs 19:12; 20:2; 30:29-31). The saying means a wicked ruler abuses power to prey on helpless, poor people. Wisdom teaches that God is a just judge who will execute justice for the poor (Proverbs 14:31; 17:5).