Psalm 149 is an action-packed psalm where singing and dancing contribute to the joy and beauty of celebrating the Lord.

The language of this psalm, especially in the second part is not about killing and cruelty but about how joy and praise in God gives us the power to overcome our lower nature and self-centred desires and urges. (See Heaven and Hell 229)

The psalm twice mentions the word 'saints'. This should not be confused with the traditional Christian view of saints. In New Christian thought, sainthood refers to a state of mind, not a person. A saint is a servant of the Lord – one who lives out his faith in life doing good. For us, we are also saints when we follow the Lord and acknowledge that everything good comes from Him. (See Apocalypse Revealed 586)

The psalm uses the word 'Let' a number of times in its first section. 'Let' carries with it the wish that something be done and brought about. This encapsulates the Lord's wish for us to know and feel His care and reciprocate in serving Him. (See Divine Providence 316)

To 'sing' means to have an affection for what is true and to be glad that we know that the Lord protects our salvation and eternal life. (See Apocalypse Explained 326) To 'sing a new song' (verse 1) is to maintain this joy in repeated new acclamations so that it is forever renewed. Similarly, dancing represents a complete and whole involvement of our joy for the Lord in our life. (See Apocalypse Explained 700)

Verse 4 contains two lovely expressions about the Lord: He takes pleasure in His people, and He will beautify the humble with salvation. These are spiritual superlatives. The first one reminds us that the Lord truly cares about the world; He is not simply an 'operator'. He takes pleasure. Pleasure brings gladness and greater connection between God and us. (See Arcana Celestia 1755) Moreover, those who are truly humble and do not assert their own self-will will be made beautiful by being saved and brought to heaven. (See Arcana Caelestia 5199)

Verse 5 speaks of the saints singing aloud on their beds. Spiritually, a 'bed' stands for our personal beliefs that support us in our life in the same way a bed supports our body in sleep. (See Arcana Caelestia 10360)

The last four verses detail the adventure our spiritual journey entails. When we choose good over evil, we subdue our adversaries in temptation and they have no power over us as we have joy in the Lord. (Arcana Caelestia 5096)

5199. 'Beautiful in appearance' means which are expressions of faith. This is clear from the meaning of 'beauty' and 'appearance'. Spiritual 'beauty' is essentially an affection for interior truth, while spiritual 'appearance' is essentially faith, so that 'beautiful in appearance' means an affection for the truth of faith, see 553, 3080, 3821, 4985. The reason spiritual beauty is an affection for interior truth is that truth is the outward form taken by good. The good which they receive in heaven from the Divine provides angels with the life they possess; but the outward form taken by that life is provided by the truths springing from that good. The truth of faith however does not provide the beauty but the affection itself present within the truths of faith springing from good. Beauty that is provided solely by the truth of faith is like the beauty of a face seen in a painting or a sculpture, but the beauty provided by an affection for truth springing from good is like the beauty of a real face full of life imparted to it by heavenly love; for as is the love - that is, as is the affection - which shines out of the form provided by the face, so is the beauty seen there. This being so, the outward appearance of the angels is indescribably beautiful. Their faces are radiant with the good of love passing through the truth of faith, which good and truth not only present themselves visually but can also be felt from the spheres that emanate from them.

[2] The reason why this is the source of beauty is that heaven in its entirety is the Grand Man and has a correspondence with every single part of the human being. Everyone therefore who has the good of love and for that reason the truth of faith present in him has the form which heaven possesses present within him; and as a consequence of this there is also imparted to him the beauty which heaven possesses, heaven being a place where the Divine going forth from the Lord is the All in all. This also explains why those in hell, being the opposite of what is good and true, are horribly ugly, and in the light of heaven do not look like human beings but like monsters. The reason why spiritual appearance (aspectus) is faith is that in the internal sense 'looking at (aspicere) and seeing' means understanding, and in a sense more internal than this having faith is meant, see 897, 2150, 2315, 2807, 3863, 3869, 4403-4421.