From the Explanations of the Psalms by Saint Ambrose, bishop
I shall sing in the spirit, and with understanding
What is more pleasing than a psalm? David expresses it well: Praise the Lord, for a song of praise is good: let there be praise of our God with gladness and grace. Yes, a psalm is a blessing on the lips of the people, a hymn in praise of God, the assembly’s homage, a general acclamation, a word that speaks for all, the voice of the church, a confession of faith in song. It is the voice of complete assent, the joy of freedom, a day of happiness, the echo of gladness. It soothes the temper, distracts from care, lightens the burden of sorrow. It is a source of security at night, a lesson in wisdom by day. It is a shield when we are afraid, a celebration of holiness, a vision of serenity, a promise of peace and harmony. It is like a lyre, evoking harmony from a blend of notes. Day begins to the music of a psalm. Day closes to the echo of a psalm.
In a psalm instruction vies with beauty. We sing for pleasure. We learn for our profit. What experience is not covered by a reading of the psalms? I come across the words: A song for the beloved, and I am aflame with desire for God’s love. I go through God’s revelation in all its beauty, the intimations of resurrection, the gifts of his promise. I learn to avoid sin. I see my mistake in feeling ashamed of repentance for my sins.
What is a psalm but a musical instrument to give expression to all the virtues? The psalmist of old used it, with the aid of the Holy Spirit, to make earth reecho the music of heaven. He used the dead gut of strings to create harmony from a variety of notes, in order to send up to heaven the song of God’s praise. In doing so he taught us that we must first die to sin, and then create in our lives on earth a harmony through virtuous deeds, if the grace of our devotion is to reach up to the Lord.
David thus taught us that we must sing an interior song of praise, like St. Paul, who tells us: I shall pray in spirit, and also with understanding; I shall sing in spirit, and also with understanding. We must fashion our lives and shape our actions in the light of the things that are above. We must not allow pleasure to awaken bodily passions, which weigh our soul down instead of freeing it. The holy prophet told us that his songs of praise were to celebrate the freeing of his soul, when he said: I shall sing to you, God, on the lyre, holy one of Israel; my lips will rejoice when I have sung to you, and my soul also, which you have set free.