This study aims to analyze the needs of female students and evaluate the validity and practicality of a Qur'anic expression-based kutayyib (pocket book) designed to support the use of Arabic in daily communication at Diniyyah Pasia Agam Contemporary Islamic Boarding School. The study was motivated by field findings indicating that although an Arabic-speaking environment has been established through language policies, scheduled learning activities, and muhadatsah programs, expressions derived directly from the Qur'an have not been systematically integrated into students' everyday communication. This situation creates a gap between formal linguistic competence and the meaningful use of Arabic grounded in Islamic values. The study employed a Research and Development (R&D) approach using the Four-D model (Define, Design, Develop, Disseminate) developed by Thiagarajan. Data were collected through participant observation, structured interviews, validated questionnaires, and documentation. The resulting product is a kutayyib containing 21 thematically selected Qur'anic expressions based on everyday situations in the boarding school environment, accompanied by contextual meanings, transliterations, and practical guidelines for daily communication. Validation results yielded an average score of 93.23%, consisting of 85% from a Qur'anic expression expert, 100% from an Arabic language expert, and 94.7% from a product design expert, all categorized as very valid. The practicality test achieved an average score of 97.35%, including 100% from teachers and 94.7% from students, indicating that the product is very practical. The findings suggest that the developed Qur'anic expression-based pocket book has the potential to support authentic daily Arabic communication while strengthening students' Islamic identity within the Islamic boarding school environment.