The Book of Psalms, which is generally believed to be the most widely read and the most highly treasured of all the books in the Old Testament, is a collection of poems, hymns, and prayers that express the religious feelings of Jews throughout the various periods of their national history. The intrinsic beauty of the poems and the sentiments that they convey have contributed toward their appreciation. Especially adapted for use in worship services, the psalms have been used in Christian churches, as well as in Jewish temples and synagogues. The Book of Psalms has a special significance for understanding the religious life of ancient Israel. The prophets and the sages provide some insight concerning what the Hebrews thought, but the psalms give the clearest indication of what the Hebrews felt. Here, we find a revelation of the hopes, the joys, the sorrows, the loyalties, the doubts, and the aspirations of the human heart.
The psalms are difficult to classify because of the wide variety of experiences and sentiments reflected in them. A further difficulty is trying to reconstruct the background or historical situation from which the different ones were produced. In the case of the prophets, this reconstruction can usually be done with a fair degree of accuracy, but not so of the psalms. They represent the inner life of individuals who lived under differing circumstances and who reacted in various ways to the critical situations that developed throughout the entire course of Israel's history. These individuals did not think alike, nor did they feel the same way about the rites and ceremonies that they observed. It would be helpful if we could know the exact circumstances that are reflected in the different psalms, but the best we can do in this respect is to find the particular occasions for which the individual psalms seem to be most appropriate. As a whole, the Book of Psalms may be regarded as a kind of epitome of the entire range of the Hebrews' religious life. It has been said that if all the rest of the Old Testament were lost, the essential faith of the Israelite people could be recovered from this single book.
The authorship of most of the psalms is anonymous, although tradition has long attributed the entire collection to King David. It is possible, but not probable, that David may have written some of them. Recent excavations and discoveries indicate quite clearly that parallels to certain of the psalms were in existence as early as the period of the monarchy, and the fact that David has been referred to as the "sweet singer of Israel" lends some support to the tradition. However, most of the psalms reflect ideas and conditions that came into existence long after the time of King David. For example, one psalm in particular discusses an event that occurred during the life of Isaiah. Others describe experiences pertaining to the Babylonian captivity, and still others appear to have originated during the period of the Maccabean wars. The earliest collection of psalms was probably titled "Psalms of David," and to this group several others were added at various times, including what was known as the "Korah Psalter," the "Asaph Psalter," the "Hallelujah Psalter," the "Pilgrim Psalter," and others. In its present form, the book is divided into five sections: Psalms 1–41; Psalms 42–72; Psalms 73–89; Psalms 90–106; and Psalms 107–150.
The psalms were used in connection with worship services conducted in the Temple at Jerusalem. Some of them were sung by the pilgrims on their journeys to the Central Sanctuary, for all of the faithful were required to attend services at this place at least once a year if it was at all possible for them to do so. Some of the hymns would be sung when the pilgrims first came in sight of the city of Jerusalem and others as they stood before the entrance to the Temple. Some of the hymns were antiphonal numbers, and their use constituted an essential part of the worship service. Hymns and prayers of adoration were used on appropriate occasions, such as the beginning of the new year, particular feast days, the enthronement of Yahweh, and celebrations of important events in Hebrew history. There were songs of praise to Yahweh for the mighty works that he had performed, and there were songs of thanksgiving for the way in which the Hebrews had been delivered from the hands of their enemies. Other songs were written in praise of the Law.
Many different themes are treated in the Book of Psalms. For example, one psalm praises Yahweh for coming to the defense of his people when the Assyrian armies invaded Judah. The sudden withdrawal of the army, leaving the city of Jerusalem standing, was indeed an occasion for great rejoicing. Yahweh's love for the poor and the oppressed is the theme of Psalm 146. Sorrow and discouragement because of the fate that befell the nation when the people were taken into captivity by a foreign power are expressed in the prayers that are recorded in Psalms 42 and 43. The same attitude can be found in Psalm 22, in which the author cries out from the depths of his soul, "My God, my God, why have you forsaken me?" The Babylonian captivity is the setting for Psalm 137, which reports, "By the rivers of Babylon we sat and wept when we remembered Zion." Psalm 119, the longest one in the entire book, is an alphabetical poem written in praise of the Law.
The psalms' teachings are difficult to summarize because their main purpose is not instruction but expressions of the heart made in the spirit of worship. Nevertheless, certain ideas are set forth in the psalms that are essential to the purposes for which they were written, including the reality and significance of Yahweh in relation to the experiences of individuals and the nation as a whole. True, the conception of Yahweh is not always the same in the different psalms, but this difference is due to the fact that each author must find for himself the conception that seems most adequate to him. Sometimes Yahweh is portrayed as a god of loving kindness and mercy, but at other times he is a god of wrath who brings destruction on those who disobey his commands. Always Yahweh is presented as an everlasting God, one who is omnipotent and omniscient, and whose power and goodness endure throughout all generations.
The Book of Psalms in the canon of the sacred Scriptures gives to the modern reader an insight into the religious life of the Hebrews that cannot be obtained from any of the other Old Testament writings. Although Jeremiah and some of the other prophets emphasized the inwardness of religion, they did so primarily to counteract the formalism that had become conspicuous in the Temple services and other practices that they observed. In Psalms, the longings, the hopes, the sorrows, and the disappointments of individual worshipers find their clearest expression. Here, we find what the various authors felt even in those situations that they were not able to understand. Although some of the psalms are probably as old as the time of King David, not until a relatively late period was the entire collection gathered and organized in the form in which it has been preserved.
Like other portions of Old Testament literature, the original psalms were edited and supplemented from time to time. Frequently we find evidence of a tendency to add something to a psalm as it first appeared in order to give to it an interpretation that would be more in accord with generally accepted ideas. For example, in Psalm 51, the first seventeen verses are written in the spirit of the great prophets, who insisted that the true worship of Yahweh consists not in sacrifices made on an altar nor in the observance of ritualistic requirements but in the inner attitudes of the human heart. The next two verses of the psalm present a very different idea, for an editor who was evidently under the influence of the post-exilic emphasis on the importance of ritual and ceremony added a statement that was intended to show that the attitude of the human heart was but a prelude to the sacrificing of bulls on the altar. It is not uncommon, even at the present time, to find hymn books that continue to use ancient conceptions, even though these have long been replaced with ideas that are more in harmony with the spirit of the times.