In origin this is an agricultural feast which arose from the needs of the farmers to seek God's help for a fruitful harvest. The farmers were at the mercy of the elements and depended upon sufficient rain and good weather. As a result they sought God's assistance and begged the intercession of Mary for their crops.
Saint Ephrem speaks of Mary in this regard when he says that Mary became of the field who received the grain of wheat in her womb and this grain of wheat, Jesus Christ our Lord, gives life to the world. Through the harvest we receive the gifts of bread and wine which become for us the body and blood of Christ in the Eucharist.