The landowner represents God.
The first group represents those who relate to God legalistically and who want to earn their blessings. The others represent those under grace who do not insist on a legal contract, but who choose to trust God’s goodness instead. They are willing to leave it to Him to give them “what is right” for them, not based upon what they do, but based upon who He is.
Those under law cannot receive anything more than they can earn. But those under grace shall always be blessed with far more than they deserve. In fact, God blesses them regardless of their performance in a manner that is way out of proportion to their performance. They get a full day’s “reward” for an hour’s worth of work.
Child of God, God is not into “fairness;” He’s into grace. He does not pay wages. He dispenses gifts. When we trust Him to give us “what is right” for us, based on His love and grace, and stop trying ourselves to earn our reward, “what is right” from God’s perspective will always be much more than we need, far beyond what we can even imagine or think.
Leave it to God to bless you and reward you. He will never bless you with less than you deserve, but He reserves the right to give you far more than you deserve; to bless you without measure! He is not fair. He is far more than fair. And that, my friend, is why I love Him so!