One who seeks access to the interior of the home, goes around to the intimate friends or members of the household to attain what he desires. In the present instance, who might these persons be? In my opinion they are the holy angels who wait on us as we pray, who offer to God the petitions and desires of men, at least of those people whose prayer they recognize to be sincere, free from anger and dissension…That the holy angels do condescend to mingle with us when we praise God in psalmody is very clearly stated by the Psalmist: The princes went before, joined with the singer, in the midst of the young damsels playing on timbrels. He also said: I will sing praise to you in the sight of the angels.
Be mindful then of these angelic princes when you go to pray or chant the psalms; stand with disciplined reverence and be proud that your angels continuously see the face of the Father. Since they are all spirits whose work is service, sent to those who will be heirs of salvation, they bear our prayers to God in heaven and return, laden with grace for us. Let us make use of the services of those in whose company our lot is cast, that by the mouths of children and babes in arms, praise may be perfect. Let us invite them: Sing praise to God, sing praise! And let us hear them responding in turn: Sing praise to our King, sing praise!
Therefore, joined as you are in songs of praise with heaven’s own singers–since you too are citizens like all the saints and part of God’s household–sing wisely! As food is sweet to the palate, so does a psalm delight the heart. But the soul that is sincere and wise will not fail to chew the psalm with teeth of the mind, as it were, because if he swallows it in a lump, without proper chewing, the palate will be cheated of the delicious flavor, sweeter than honey from the comb.