"To rejoice in the Lord--to trust, confide, glory and have pride in the Lord as in a gracious Father--this is a joy which rejects all else but the Lord, including that self-righteousness whereof Jeremiah speaks (9:23-24): 'Let not the wise man glory in his wisdom, neither let the mighty man glory in his might, let not the rich man glory in his riches; but let him that glorieth glory in this, that he hath understanding, and knoweth Me.'"
Sermons of Martin Luther, 8 vols., ed., John Nicholaus Lenker, Grand Rapids: Baker Book House, 1983, VI, p. 95. Fourth Sunday in Advent, Philippians 4:4-7; Jeremiah 9:23-24.