If someone sees a public notice asking people to pray for a sick person, is there an obligation to pray?

This source-based Torah study examines the question: If someone sees a public notice asking people to pray for a sick person, is there an obligation to pray? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions, and practical implications of the original text. This localized discovery layer does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.