Isaiah 49:23

And kings shall be thy nursing fathers - Margin, ‘Nourishers.’ That is, they would patronize the church of God; they would protect it by their laws, and foster it by their influence and become the personal advocates of the cause of Zion. The idea is properly that of guarding, educating, and proriding for children; and the sense is that kings and princes would evince the same tender care for the interests of the people of God which a parent or a nurse does for a child. It is needless to say that this has been already to a considerable extent fulfilled, and that many princes and monarchs have been the patrons of the church, though doubtless it is destined to a more ample fulfillment still in the brighter days of this world’s history, when the gospel shall spread everywhere. It is remarkable that, in the Sandwich and South Sea Islands, the Christian religion has been uniformly, almost, taken under the protection of the kings and chiefs since its first introduction there, and has been carried forward and extended under their direct authority.

They shall bow down to thee with their face toward the earth - A posture indicating the profoundest reverence. This is the common posture of showing great respect in the East.

And lick up the dust of thy feet - An act denoting the utmost possible respect and veneration for the church and people of God.

For they shall not be ashamed that wait for me - They who worship me shall not be ashamed of the act requiring the deepest self-abasement, to show their reverence for me. Even those of most elevated rank shall be willing to humble themselves with the profoundest expressions of adoration.