[Scriptum compendiosum Psalterii intentionem declarans]

Resting in his bed he is seized by sleep. It seemed as if all the breath he had expired while singing to the honor of God was breathing back from the heart of God. Having woken up, therefore, he felt himself entirely comforted and entirely recreated, and from that time he sang with even greater fervor. But clamorous and broken singing, which is done not for the praise of God but for vain glory, God considers little, but the demon approves. Whence Caesarius reports that on a certain festival, while certain clerics were singing and lifting their tumultuous voices on high, a certain religious man saw a certain demon in a higher place of the church holding a large sack in his left hand, and with his right hand he was putting the voices of the songs into the same sack. But to those boasting among themselves after the song was finished, as if they had praised God well and powerfully, he who had seen the vision responded: "You sang well indeed, namely a sack full of songs." To those wondering and asking why he said this, he explained the vision. The same man also reports that in a certain Cistercian monastery, while the monks were beginning the psalms with a moderate voice and following him in the same way, a youth, arrogant enough, raised his voice beyond the third tones, and although the seniors were resisting him, he, with certain others assisting his part, prevailed, and thus he became a scandal to the seniors. Soon a demon, like glowing iron, went out from his mouth toward those who had helped him. When, however, the brothers stand in the choir for the divine office, let everyone be careful lest he be sluggish and fastidious, but let the choir compel the spirit to stand reverently and to sing to God alacritously before the angels who are present there. For the Psalmist says:

In the sight of the angels I will sing to you.
Let a brother utterly detest laughter and useless words where he ought to assist the Lord of majesty with fear and reverence. Let him pronounce the words of psalmody distinctly and integrally, not by syncopating nor by accelerating too much. Whence Bernard on the Canticles, in his forty-eighth sermon, admonishes his brothers, saying:
I admonish you, most beloved boys, always and strenuously always to be present at divine praises. Strenuously indeed, so that you may be reverent; thus also that you may assist the Lord alacritously, not sluggish, not sleepy, not yawning, not omitting voices, not skipping.