Matthew 18:21-35 (Year A, p. 399):

21 Peter came and said to Jesus, “Rabbi, if a sister or brother sins against me, how often should I forgive? Up to seven times?” 22 Jesus said to him, “Not seven times, but, I tell you, seventy-seven times.
23 “For this reason the realm of heaven may be compared to a human ruler who wished to settle matters with their enslaved debtors. 24 When the settlement began, one who owed ten thousand talents was brought forward. 25 Since that one could not pay, the ruler ordered that enslaved person to be sold, together with spouse and children and every possession, and thus to pay. 26 So falling and kneeling before the ruler, the enslaved debtor said, ‘Have patience with me, and I will pay you everything.’ 27 And out of compassion, the lord of that enslaved person released that one and forgave the debt. 28 But that same enslaved person who was owed a hundred denarii by another enslaved person, upon going out, came upon the debtor; and seizing that one by the throat, said, ‘Pay what you owe.’ 29 Then the indebted slave fell down and pled, ‘Have patience with me, and I will pay you.’ 30 But the other enslaved person was not willing and went and threw the debtor into prison until the debt was paid. 31 When those who were also enslaved saw what had happened, they were greatly distressed, and they went and reported to their lord all that had taken place. 32 Then the lord summoned the one whose debt was forgiven saying, ‘You wicked slave! I forgave you all that debt because you pleaded with me. 33 Should you not have had mercy on your fellow slave, as I had mercy on you?’ 34 And in anger the lord handed that one over to be tortured until the entire debt could be paid. 35 So my heavenly Abba will also do to every one of you, if you do not forgive your sister or brother from your heart.”