Matthew Henry and continuators on Proverbs 20:28

28 Mercy and truth preserve the king: and his throne is upholden by mercy.

Here we have, 1. The virtues of a good king. Those are mercy and truth, especially mercy, for that is mentioned twice here. He must be strictly faithful to his word, must be sincere, and abhor all dissimulation, must religiously discharge all the trusts reposed in him, must support and countenance truth. He must likewise rule with clemency, and by all acts of compassion gain the affections of his people. Mercy and truth are the glories of God's throne, and kings are called gods. 2. The advantages he gains thereby. These virtues will preserve his person and support his government, will make him easy and safe, beloved by his own people and feared by his enemies, if it be possible that he should have any.