The readings for Ordinary Time are related, both within a given Sunday and between Sundays. In last Sunday's Old Testament reading, God tells us that “my ways are above your ways, and my thoughts are above your thoughts.” In the Gospel for last Sunday, we get to see what that means in practice, through a parable.
In that parable, the landowner stands for God. If the people who only worked one hour get paid for a full day's work, then the people who actually worked a full day should get paid even more - but they don't.
To our notions of fairness, what the landowner does is just plain wrong. It's not fair!
"It's not fair!" is a powerful accusation, and God is not about to let it go unanswered. This Sunday's Old Testament reading is God's response, and it's just as powerful.
More on this tomorrow.
Sunday’s Readings: http://www.usccb.org/bible/readings/092814.cfm