The hymnography of a feast developed around the biblical readings placed in their structure as direct references to the celebrated saving event. Especially in the monastic rite, hymns and chants gained credibility in terms of doctrinal correctness when they did not deviate from the scriptural skeleton that influenced it. Following the system of bible readings during a feast helps us to extract their main theme and how to celebrate the event referred to. The Evangelical and Apostolic readings occupy a central place in the structure of a feast, around which the other elements were carved. Through them we can know what themes the Feast of Pentecost covered over time.