"Although the whole of Scripture breathes God's grace upon us, this is especially true of the most delightful book, the Book of the Psalms. Moses, when he told of the deeds of the patriarchs, did so in a plain and unadorned style. But when he had miraculously led the people of Israel across the Red Sea, and when he had seen King Pharaoh with all his army drowned, he transcended his own normal style and sang a song of triumph to the Lord - just as through the miracle Moses' powers were transcended by God's. Miriam the prophetess took up a timbrel and led the others in the refrain 'Sing to the Lord: he has covered himself in glory, horse and rider he has thrown into the see.' (Ex 15:21)
History instructs us, the law teaches us, prophecy foretells, rebuke condemn us, wisdom persuades us; but the book of Psalms goes further than all of these. It is medicine for our spiritual health. When we read it we find a medicine to cure the wounds caused by any of our passions. Whoever studies it deeply will find it to be like a gymnasium for their soul, where the different psalms are like different exercises set out before them. In that gymnasium, in that stadium of virtue, they can choose the exercises that will best train them to win the victors crown."
- St. Ambrose of Milan
From
Awakening Faith: Daily Devotions from the Early Church, #340