The Pentecost feast found its expected celebration in the usual sequence of Jewish festival days that became part of the Jewish calendar in connection with the Exodus. Pentecost was, accordingly, an annual Jewish festival; but this particular Pentecost found a unique situation and expression because it succeeded Jesus’ recent resurrection.
Each of the feasts were to be annually observed as a reminder of God’s deliverance of Israel from Egypt to the land of promise. One feast, though, was never to be celebrated without the others, for, together, they recited a single narrative and history.
The meaning of scripture, in this way, is the gift of God to the questions that he, himself, excites in man. This is illustrated on Pentecost day, in the litany of strange phenomena that overtakes the crowd that is gathered in Jerusalem.