The psalter is the prayer book of Israel, the treasury of Israel's hopes and fears, successes and failures, loves and hates. For centuries the Psalms have provided the material for monastic and priestly prayer, and in every age have been used to express the prayers of Christians in moments of crisis or joy. Since the revival of the use of the Liturgy of the Hours, the 150 psalms have again become increasingly important as a vehicle and expression of worship .Introduced by Henry Wansborough, OSB, who also gives practical guidance for personal reading and reflection. The Grail translation is that used in the Liturgy of the Hours and the Mass.