The general ethical proverb is here followed by one that is political:

2 When the righteous increase, the people rejoice;

   And when a godless man ruleth, the people mourn.

Regarding 'בּרבות צדּ (Aquila rightly, ἐν τῷ πληθῦναι δικαίους), vid., at Proverbs 28:28. If the righteous form the majority, or are in such numbers that they are the party that give the tone, that form the predominant power among the people (Fleischer, cum incrementa capiunt justi), then the condition of the people is a happy one, and their voice joyful (Proverbs 11:10); if, on the contrary, a godless man or (after Proverbs 28:1) godless men rule, the people are made to sigh (יאנח עם, with the Gaja, according to rule). "There is reason," as Hitzig remarks, "why עם should be placed first with, and then without, the article." In the first case it denotes the people as those among whom there is such an increase of the righteous; in the second case, the article is wanting, because it is not generally used in poetry; and, besides, its absence makes the second line consist of nine syllables, like the first.

Proverbs 29:8 Parallel Commentaries

scornful

Proverbs 11:11 By the blessing of the upright the city is exalted: but it is overthrown by the mouth of the wicked.

Isaiah 28:14-22 Why hear the word of the LORD, you scornful men, that rule this people which is in Jerusalem...

Matthew 27:39-43 And they that passed by reviled him, wagging their heads...

John 9:40,41 And some of the Pharisees which were with him heard these words, and said to him, Are we blind also...

John 11:47-50 Then gathered the chief priests and the Pharisees a council, and said, What do we? for this man does many miracles...

1 Thessalonians 2:15,16 Who both killed the Lord Jesus, and their own prophets, and have persecuted us; and they please not God, and are contrary to all men...

bring a city into a snare or set a city on fire

James 3:5,6 Even so the tongue is a little member, and boasts great things. Behold, how great a matter a little fire kindles!...

wise

Exodus 32:10-14 Now therefore let me alone, that my wrath may wax hot against them, and that I may consume them: and I will make of you a great nation...

Numbers 16:48 And he stood between the dead and the living; and the plague was stayed.

Numbers 25:11 Phinehas, the son of Eleazar, the son of Aaron the priest, has turned my wrath away from the children of Israel...

Deuteronomy 9:18-20 And I fell down before the LORD, as at the first, forty days and forty nights: I did neither eat bread, nor drink water...

2 Samuel 24:16,17 And when the angel stretched out his hand on Jerusalem to destroy it, the LORD repented him of the evil...

Jeremiah 15:1 Then said the LORD to me, Though Moses and Samuel stood before me, yet my mind could not be toward this people...

Ezekiel 22:30 And I sought for a man among them, that should make up the hedge, and stand in the gap before me for the land...

Amos 7:2-6 And it came to pass, that when they had made an end of eating the grass of the land, then I said, O Lord GOD, forgive, I beseech you...

James 5:15-18 And the prayer of faith shall save the sick, and the Lord shall raise him up; and if he have committed sins...