Isaiah 11:5 - Joseph Benson’s Commentary on the Old and New Testaments

And righteousness shall be the girdle of his loins It shall adorn him, and be the glory of his government, as a girdle was used for an ornament, Isaiah 3:24; and as an ensign of power, Job 12:18; and it shall constantly cleave to him in all his administrations, as a girdle cleaveth to a man's loins. And faithfulness the girdle of his reins The same thing in other words. Here then we have the basis and foundation of this kingdom, namely, the justice and fidelity of the king. These virtues shall be conspicuous in the whole administration of his government, and, at once, be the ornament and the support of it. “The sum is, that the kingdom of Christ should be a kingdom of the highest equity, and the king of it perfect: who, though judging his true subjects by the law of grace, by faithfully performing all the promises of the gospel, and every condition of the covenant to them, will yet not omit to punish the enemies of his church according to their deserts, and thus to satisfy the law of justice: so that he shall not be less venerable and awful for his justice in judgment, than amiable and desirable for his truth, fidelity, and constancy in performing his promises; which being things naturally united, are not, by any means, to be separated.” Dodd.