Albert Barnes on Matthew 20:13

Friend, I do thee no wrong. I have fully complied with the contract. We had an agreement; I have paid it all. If I choose to give a penny to another man if he labours little or not at all; if I should choose to give all my property away to others, it would not affect this contract with you. It is fully met. And with my own-- with that on which you have no further claim--may do as I please. So, if Christians are just, and pay their lawful debts, and injure no one, the world has no right to complain if they give the rest of their property to the poor, or devote it to send the gospel to the heathen, or to release the prisoner or the captive. It is their own. They have a right to do with it as they please. They are answerable not to men, but to God. And infidels, and worldly men, and cold professors in the church, have no right to interfere.

(d) "Friend" Mt 22:12