So then, my son, let whoever reads this Book of Psalms take the things in it quite simply as God-inspired; and let each select from it, as from the fruits of a garden, those things of which he sees himself in need. For I think that in the words of this book all human life is covered, with all its states and thoughts, and that nothing further can be found in man. For no matter what you seek, whether it be repentance and confession, or help in trouble and temptation or under persecution, whether you have been set free from plots and snares or, on the contrary, are sad for any reason, or whether, seeing yourself progressing and your enemy cast down, you want to praise and thank and bless the Lord, each of these things the Divine Psalms show you how to do, and in every case the words you want are written down for you, and you can say them as your own.
-from his letter to Marcellinus, On the Interpretation of the Psalms
The rest of which (it's long) you can read here.
-from his letter to Marcellinus, On the Interpretation of the Psalms
The rest of which (it's long) you can read here.