4 What then follows, since he has said, “Unto You do I lift up my eyes”?. How have you lifted up your eyes? “Behold, even as the eyes of servants look unto the hand of their masters, and as the eyes of a maiden unto the hand of her mistress: even so our eyes wait upon the Lord our God, until He have mercy upon us.” We are both servants, and a handmaiden: He is both our Master and our Mistress. What do these words mean? What do these similitudes mean? It is not wonderful if we are servants, and He our Master; but it is wonderful if we are a maiden, and He our Mistress.
But not even our being a maiden is wonderful; for we are the Church: nor is it wonderful that He is our Mistress; for He is the Power and the Wisdom of God...When therefore you hear Christ, lift up your eyes to the hands of your Master; when you hear the Power of God and the Wisdom of God, lift up your eyes to the hands of your Mistress; for you are both servant and handmaiden; servant, for you are a people; handmaiden, for you are the Church. But this maiden has found great dignity with God; she has been made a wife.
But until she come unto those spiritual embraces, where she may without apprehension enjoy Him whom she has loved, and for whom she has sighed in this tedious pilgrimage, she is betrothed: and has received a mighty pledge, the blood of the Spouse for whom she sighs without fear. Nor is it said unto her, Do not love; as it is sometimes said to any betrothed virgin, not as yet married: and is justly said, Do not love; when you have become a wife, then love: it is rightly said, because it is a precipitate and preposterous thing, and not a chaste desire, to love one whom she knows not whether she shall marry.
For it may happen that one man may be betrothed to her, and another man marry her. But as there is no one else who can be preferred to Christ, let her love without apprehension: and before she is joined unto Him, let her love, and sigh from a distance and from her far pilgrimage...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)