[Scriptum compendiosum Psalterii intentionem declarans]

And most certainly, from this, many fruits and utilities, already seen, having passed over the distractions incident through various thoughts, most of the phantasms falling by the instinct and suggestion of the devil and dangerously impeding those praying and singing, are more easily avoided; the tedium of praying and singing by night and day is better removed; one rejoices all the more in being present at the divine office; one is not deprived of the fruit of one's prayers; one's merit is increased; and the whole court of heaven is gladdened and delighted. Whence, for the sake of these things, before one approaches the exposition of the letter, some things are to be prefixed as useful for ecclesiastical men and especially religious ones. And because, as it was said, a psalm is called the praise of God with a song, first it must be seen regarding the utilities of vocal song; second, regarding the manner of singing and chanting; third, regarding the attention to be exhibited in the divine office and other prayers; fourth, how one ought to prepare oneself for prayer; fifth, regarding the instance of prayer and its being heard.

Regarding the first, where it must be seen regarding the utilities of vocal song, it is to be noted that although heretics censure the vocal songs of the Church, nevertheless the Church did not institute them without great reason,

for a song or jubilation of this kind has many effects. One is that it brings the things of heaven into the affection; whence it is written concerning our blessed father Augustine: "He was weeping very abundantly in the hymns and canticles of the Church sounding sweetly, by which vehement affection." Also, it elevates the mind; it lifts the eyes of the heart on high; it is the jubilation of praise, whence many are caught up in ecstasy in a jubilation of this kind. And therefore, after it is said in the psalms "In the churches bless the Lord God," it follows there "Benjamin in the ecstasy of the mind." Also, it repels evil sadness; the gloss upon that word of James the fifth, "Is any of you sad?" etc., says that it frequently repels the plague of harmful sadness through the sweetness of psalmody. Therefore David says: "My lips will exult," that is, it is so filled with joy that it will appear in the lips when I have sung to you. Also, it prepares the way of the heart for the Lord for the infusion of multiform graces. Gregory on Ezekiel: "When the way to the heart is prepared for almighty God through the infusion of psalmody," the psalmist says: "Sing a psalm to his name; and thus make a path for him." And in the fourth book of Kings: "When the psalmist sang, the hand of the Lord was upon him." And these are four effects in the soul. Also, it puts the devil to flight; in 3 Kings 16, David would take the cithara and play with his hand, and he would play and it would become better: for the evil spirit was departing from him. Also, it delights God; whence Ecclesiastes says in the canticles: "Let your voice sound in my ears." Also, it turns the militant Church into the likeness of the triumphant one, which always jubilates. Bernard on the Canticles: "Nothing on earth so closely represents a certain state of heavenly habitation as the alacrity of those praising God." Also, it confounds the enemies of the Church; in 2 Paralipomenon 20: "When they had begun to give praises, the Lord turned the ambushes of the enemies and they suffered." Happy are those effects, and happy is the jubilation that resolves the hardness of the heart, that elevates the earthly mind, that dispels the sadness of the world, that prepares for the reception of divine benediction, that puts the devil to flight, delights God, assimilates the militant Church to the triumphant one, and confounds its hosts. Therefore, how useful and how healthy it is to sing and to frequently chant the psalms devoutly because of those fruits and effects, and many others even previously touched upon.