34 Righteousness exalteth a nation: but sin is a reproach to any people.
Note, 1. Justice, reigning in a nation, puts an honour upon it. A righteous administration of the government, impartial equity between man and man, public countenance given to religion, the general practice and profession of virtue, the protecting and preserving of virtuous men, charity and compassion to strangers (alms are sometimes called righteousness), these exalt a nation; they uphold the throne, elevate the people’s minds, and qualify a nation for the favour of God, which will make them high, as a holy nation, Deut. xxvi. 19.
2. Vice, reigning in a nation, puts disgrace upon it: Sin is a reproach to any city or kingdom, and renders them despicable among their neighbours. The people of Israel were often instances of both parts of this observation; they were great when they were good, but when they forsook God all about them insulted them and trampled on them. It is therefore the interest and duty of princes to use their power for the suppression of vice and support of virtue.
– Matthew Henry Commentary