Praise and lament are two major approaches to praying to God. Westermann investigates these primary categories of the Psalms and shows their meaning for prayer and worship. He contrasts the Old Testament Psalms with those of Babylon and Egypt indicating their distinctive characteristics. Westermann divides Psalms of praise into two types: declarative and descriptive. He then relates praise to lament and demonstrates how the Psalms move from supplication to praise.