Proverbs 20:28

28 Love and truth guard the king; And he supports his throne by love. We have not in the German [nor in the Eng.] language a couple of words that completely cover חסד ואמת; when they are used of God, we translate them by grace and truth [Gnade u. Wahrheit], Psa 40:12 (יצּרוּני); when of men, by love and truth [Liebe u. Treue], Pro 16:6; and when of the two-sided divine forces, by kindness and truth, Pro 3:3. Love and truth are the two good spirits that guard the king. If it is elsewhere said that the king's throne is supported "with judgment and with justice," Isa 9:6 [7]; here, on the other side, we see that the exercise of government must have love as its centre; he has not only to act on the line of right, שׁוּרת הדּין; but, as the later proverb says, in such a way, that within this circle his conduct is determined by the central motive of love. In this sense we give the king not only the title of Grossmchtigster [most high and mighty], but also that of "Allergndigster" most gracious, for the king can and ought to exercise grace before other men; the virtue of condescension establishes his throne more than the might of greatness.

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.

20:28 God’s unfailing love and faithfulness are closely connected to his covenant with his people (see Exod 34:5-7; Deut 7:7-9). The king represents God on earth, so God will protect him (see 2 Sam 7).