Introduction to Psalm 150

The last psalm of the psalter, and the final psalm of Lauds each day, Psalm 150, serves as a doxology to the whole book, conjuring up an image of the celestial liturgy played out with voices and orchestra, as the universe reverberates with praise for the greatness of God.

Psalm 150: Laudate Dominum

Vulgate	Douay-Rheims
Alleluja.	Alleluia
Laudáte Dóminum in sanctis ejus: * laudáte eum in firmaménto virtútis ejus.	Praise the Lord in his holy places: praise him in the firmament of his power.
2  Laudáte eum in virtútibus ejus: * laudáte eum secúndum multitúdinem magnitúdinis ejus.	2 Praise him for his mighty acts: praise him according to the multitude of his greatness.
3  Laudáte eum in sono tubæ: * laudáte eum in psaltério, et cíthara.	3 Praise him with the sound of trumpet: praise him with psaltery and harp.
4  Laudáte eum in tympano, et choro: * laudáte eum in chordis, et órgano	4 Praise him with timbrel and choir: praise him with strings and organs.
5  Laudáte eum in cymbalis benesonántibus: laudáte eum in cymbalis jubilatiónis: * omnis spíritus laudet Dóminum.	5 Praise him on high sounding cymbals: praise him on cymbals of joy: 6 Let every spirit praise the Lord. Alleluia

The culmination of the Book of Psalms

The psalm consists of ten separate calls to praise God -  a number that the Fathers associated both with the 'ten words' of creation, and the ten commandments.  

The number is moreover, increased to twelve in Scripture (though not in the liturgical version of the text), a number symbolising universality, by the addition of an alleluia at the beginning and end of the psalm.

Many commentators see this psalm as encapsulating the outcome of praying the psalter: in Psalm 1, we are invited to meditate on the law day and night; if we do so, we will reach the state of ecstatic praise described in Psalm 150 that unites together heaven and earth (v1).

God's saving action

The psalm does not linger on the reasons for praising God: verse 2 points simply to his greatness, and 'mighty acts', the most important of which for our salvation is the Resurrection.

Instead, the psalm describes the various instruments that should be devoted to the praise of God, which the Fathers typically interpreted as reflecting different aspects of Christian life, such as obedience to God's commands, suppression of sinful physical desires, of belief, moral excellence and desire for it and his salvation.

Cassiodorus sees the psalm as portraying a gradual ascent towards heaven:

See how once again that herald of salvation is brought back before us, to speak not of bodily sustenance but of heavenly abundance. The city of God is urged to gather from the circumference of the world, and to sing with tongue and heart. So let us sing with total concentration this Alleluia, which through the Lord's ordering has brought the entire corpus of psalmody to its high point. Just as transient earthly fire hastens to the upper regions and raises its ruddy crest to a peak, so this psalm gradually grows and flits upward to the heights of heaven by the steps of the virtues. If with the support of the Lord's right hand we too mount with it in devotion of spirit, we shall be granted access to the End which brings salvation, and which is bounded by no limits.

And it ends, in his view, on a note that signals the Church Triumphant:

It is short, so that it may not induce weariness; it abounds in musical instruments, so that it could be made most suit­able for spiritual marriage, and could be sung with marital joy in the assembly of the heavenly Jerusalem. Its purpose is praise by the saints' gathering to the Lord, who has restored them to His image and caused them to lay aside the frailty of flesh and blood. He has now set them in that blessedness to conform with His glory, so that they may be filled with abundance of all blessings. As Paul says of them: He has blessed us with all spiritual blessings, so that we should be holy and unspotted in his sight…

Liturgical uses of the psalm

NT references	1 Cor 13:1; Rev 5:13(5)
RB cursus	daily Lauds+AN 3282 (1), 3303(4), 3218 (5)
Feasts etc	AN 3283 (1), 4154 (6)
Responsories	-
Roman pre 1911	Daily Lauds
Roman post 1911	1911-62:Sat Lauds  . 1970:
Mass propers (EF)	-

You can find verse by verse notes on this psalm starting here.