The Enchiridion 43 : 1

Everything has two handles: one by which it may be borne, another by which it cannot. If your brother acts unjustly, do not lay hold on the affair by the handle of his injustice, for by that it cannot be borne, but rather by the opposite—that he is your brother, that he was brought up with you; and thus you will lay hold on it as it is to be borne.