Article Pentecost and the Harvest How the Feast of Weeks Foreshadowed the Harvest to Come by Alison Dellenbaugh on May 25, 2023 The Feast of Weeks, also known as Pentecost, was a festival instituted by God in the Old Testament to celebrate the harvest. When God sent the Holy Spirit at Pentecost as described in Acts, He simultaneously ushered in a new spiritual harvest.