The answer is: Some had worked less hours for the same pay

Matt 20:1-16 - Such is the kingdom of heaven. Some may labour in the Lord's vineyard for longer, but the reward is the same.

The parable of the workers in the vineyard is not just about wages; it's about perspective and fairness. Picture this: a group of laborers starting their day in a vineyard. Some toil in the scorching sun from dawn till dusk, while others arrive only an hour before quitting time. When it comes time for payment, everyone receives the same amount — one penny. The early workers feel unfairly treated, grumbling about their efforts compared to those who worked a fraction of the time.

This story unveils deeper themes of generosity and grace. The vineyard owner, representing a divine authority, reflects an unexpected kindness that can baffle human ideas of justice and merit. It's a gentle reminder that in life (and especially in spiritual matters), the measure of one's worth isn't confined to hours logged or efforts churned out. The owner’s response, "Are you envious because I am generous?" invites us to reconsider our own judgments regarding value and reward.

Historically, labor and reward have significance in many cultural traditions! The Hebrew concept of the vine—often symbolic of Israel—adds layers to this parable, suggesting that all are invited into this kingdom regardless of when they say yes. Scripture often employs vineyards, signifying vitality and nourishment. This parable beautifully weaves together the idea that everyone's contribution, regardless of timing, is valuable in the grand scheme of the divine. So next time we feel discontent over life’s perceived inequalities, we might take a lesson from this vineyard and appreciate the boundless generosity that surrounds us.