Tertullian, Against Marcion 35

He turned to the disciples and addressed the author of scandals: 'It would have been better for him had he never been born, or had he been thrown into the depths with a millstone tied around his neck, than to scandalize one of these little disciples of mine.' Weigh the kind of punishment He threatens. No one else will avenge the scandal of His disciples. Recognize, then, both the Judge and the One who speaks out of care for His own with the same affection the Creator once showed: 'Whoever touches you touches the apple of My eye' (Zech 2:8). The sense is identical. He commands us to rebuke a sinning brother; whoever refuses has already failed — either out of hatred, wanting the brother to persist in his fault, or out of favoritism, sparing him. You have Leviticus: 'You shall not hate your brother in your heart; you shall surely rebuke your neighbor, and not bear sin because of him; you shall not take vengeance' (Lev 19:17–18). No wonder He teaches this way, when He even forbids ignoring your brother's straying livestock so that you might return them — how much more the brother himself. But He also commands you to forgive a brother who sins against you, even seven times. Plainly that's not enough. For with the Creator it goes further: He sets no limit, declaring it to infinity — 'Do not remember your brother's malice, and do not grant it to the one who asks, nor even to the one who does not ask.' He does not want you to give offense, but to forget. The law of lepers — how great its interpretation regarding the very nature of that vice and the inspection of the high priest — will be our task to know, Marcion, so we can oppose the law's moroseness and affirm Christ here as its rival, anticipating its solemnities even in the healing of the ten lepers. He merely ordered them to go show themselves to the priests, and He cleansed them on the way, without touch now and without a word, by silent power and sheer will.