St. Isidore composed this document to serve as a foundational guide for monastic living, addressing various aspects of monastic life, including the structure and discipline of a monastery, the selection and qualities of an abbot, and the expected virtues and behaviors of monks. It emphasizes the significance of unity, humility, and adherence to the teachings of the apostles. The text also advises on the physical layout of the monastery to ensure both safety and spiritual focus, highlighting the need for a supportive community that fosters spiritual growth and obedience to God.