"I have calmed and quieted my soul..."

A blog post this morning called my attention to Psalm 131:

O LORD, my heart is not lifted up,
     my eyes are not raised too high;
I do not occupy myself with things
     too great and too marvelous for me.
But I have calmed and quieted my soul,
     like a child quieted at its mother’s breast;
     like a child that is quieted is my soul.
O Israel, hope in the LORD
     from this time forth and for evermore.