What does Matthew 20:12 mean?
A group of laborers hired early in the morning to do a day's work in the vineyard in exchange for one denarius each are grumbling. Have they not been paid? Has their pay been delayed? Was the work different than expected? Was the master harsh with them? No, none of this has happened. The workers explain that they are upset because others were paid the same amount despite working only one hour. They worked hard all day long, and it was hot.None of their complaints are false. Israel's midday heat can be extreme for those who don't escape into shade. Ten to twelve hours is a long workday and harvesting in a vineyard can be grueling work. If the agreements made by the master had been to pay based on merits or under any merit-based system of pay or reward, the group hired early in the morning deserved ten times more than the group hired to close out the day.
The point of Jesus' parable, though, will be that the kingdom of heaven does not run on a merit-based system. It runs on the grace of God toward those who come to Him through Jesus, no matter when they come or what they seemingly deserve. Even more to the point, those who came to the Master earlier are not being cheated—they are obtaining exactly what was promised.