From the additional notes to Charles Spurgeon's The Treasury of David, Psalm 113:
Verse 6. Who humbleth himself. Whatever may be affirmed of God, may be affirmed of him infinitely, and whatever he is, he is infinitely. So the psalmist, in this place, does not speak of God as humble, but as infinitely and superlatively so, humble beyond all conception and comparison; he challenges the whole universe of created nature, from the highest immortal spirit in heaven to the lowest mortal on earth, to show a being endued with so much humility, as the adorable majesty of the great God of Heaven and earth...If some instances of the Divine humility surprise, the following may amaze us: To see the great King of heaven stooping from his height, and condescending himself to offer terms of reconciliation to his rebellious creatures! To see offended majesty courting the offenders to accept of pardon! To see God persuading, entreating and beseeching men to return to him with such earnestness and importunity, as if his very life were bound up in them, and his own happiness depended upon theirs! To see the adorable Spirit of God, with infinite long suffering and gentleness, submitting to the contempt and insults of such miserable, despicable wretches as sinful mortals are! Is not this amazing?—Valentine Nalson, 1641-1724.
[Nalson, known mostly for his Sermons on Twenty Topics was the son of the slightly more famous Valentine Nalson.]