Adam Clarke on Psalms 131:1

Lord, my heart is not haughty - The principle of pride has no place in my heart; and consequently the high, lofty, and supercilious look does not appear in my eyes. I neither look up, with desire to obtain, to the state of others, nor look down with contempt to the meanness or poverty of those below me. And the whole of my conduct proves this; for I have not exercised myself - walked, in high matters, nor associated myself with the higher ranks of the community, nor in great matters, נפלאות niphlaoth, wonderful or sublime things; too high for me, ממני mimmeni, alien from me, and that do not belong to a person in my sphere and situation in life.