A book titled Prayer by A. Hamman is most likely a theological or spiritual work on the subject of prayer, rather than a work of fiction with a specific plot or characters. Without direct access to a specific text, the main themes of the book are likely to include: The Nature and Importance of Prayer: An exploration of what prayer is and its role in spiritual or religious life. Forms of Prayer: An analysis of various types of prayer, such as prayers of praise and adoration, petition, intercession (praying for others), and thanksgiving. Historical or Patristic Dimension: Given that A. Hamman's name is often associated with the writings of the Church Fathers (Patristics), the book likely addresses how prayer was practiced and understood in the ancient Christian tradition. In short, the book is likely a rich resource of theological and historical insights into the practice and understanding of prayer in the context of a particular religious faith.