Envy versus generosity: In Matthew’s church, the image of a vineyard would have been readily recognized. The vineyard represented Israel; the landowner, God. The vineyard owner repeatedly hires workers: God never ceases to invite his people into his kingdom.
However, no one invited to the kingdom is any greater than anyone else. God rewards not according to any kind of human standard, but according to God’s own standards of equality. Thus, those who worked only one hour receive the same pay as those who worked all day.
The parable warns the members of Matthew’s church. No one in the community can claim a greater reward than anyone else. God, who is just, distributes his gifts as he wills. Those who work long hours will inherit the kingdom alongside those who come into the vineyard late.