That day’s great gathering of Jews from all over the Mediterranean area lets us know that before the Spirit came down on the Apostles the day of Pentecost had some non-Christian history. Knowledge of that pre-Christian history adds depth to our appreciation of this great feast.
From a thousand years before the brothers of Joseph sold him down into Egypt, the peoples of the Middle East were celebrating their own version of Pentecost. They always planted grain in November, then, they began their harvesting on the day of the first full moon in spring. That night they would use the first grain for flat cakes mixing no yeast with the dough. After that night, to get their harvest in before the late spring rains, they would work from sun up to sun down for fifty days, getting in the harvest. The word Pentecost meant fiftieth day. On Pentecost they would celebrate the end of the tiring harvesting. They’d party. They’d have weddings.
For the Israelites Pentecost took on a new meaning. The Book of Exodus tells us that they ate their first Passover meal the night of the feast of the unleavened bread. Then they journeyed the length of the Sinai Peninsula over the next seven weeks. On the day of Pentecost they made their covenant with God on the plain in front of Mt. Sinai. It was as though they were completing a spiritual harvest.
When the Spirit-filled Apostles emerged from the upper room they found the streets thronged with visitors. They were celebrating both the anniversary of the Israelite’s covenant with God, and the end of the fifty-day-long back-bending work in the fields.
Our spiritual harvest season began with the Lord offering us the unleavened Bread of the Eucharist. It ends with the Spirit bringing everything together in the minds of the Apostles. They came out from hiding in the upper room, and Peter explained all the Spirit had enabled him to see.