John Gill Commentary Isaiah 11:5

"And righteousness shall be the girdle of his waist, and faithfulness the girdle of his loins." — Isaiah 11:5 (ASV)

And righteousness shall be the girdle of his loins
He shall be adorned with it, strengthened by it, and ready at all times to perform it; he loved righteousness, and did acts of righteousness throughout the whole course of his life; and, by his active and passive obedience, wrought out an everlasting righteousness for his people; he is a King that reigns in righteousness, righteousness is the sceptre of his kingdom; all his administrations of government are righteous; just and true are all his ways:

and faithfulness the girdle of his reins ;
he was faithful to God, that appointed him as King and Head of the church; faithful as a Prophet, in declaring his mind and will; and is a faithful High Priest, as well as a merciful one. The Targum, interprets this of righteous and faithful men, thus, ``and the righteous shall be round about him, and they that work (the work) of faith shall draw nigh to him;'' but it is said of a single person, of the Messiah only, to whom it properly belongs.