Do not permit your children to argue and quarrel with one another and call one another names and grumble at one another. Neither must they give one another negative nicknames but sincerely love, tolerate, help, and be friendly to one another. This is also how they must behave toward others. Teach them the following texts: “The works of the flesh are hatred, quarrels, jealousy, wrath, strife, seditions” (Gal. 5:19-20). “Anyone who says to his brother, ‘You fool!’ will be in danger of the fire of hell” (Matt. 5:22). “A soft answer turns away wrath, but grievous words stir up anger” (Prov. 15:1). “Behold how good and pleasant it is for brothers to dwell together in unity! . . . For there the LORD commanded the blessing, even life for evermore” (Ps. 133:1, 3). Talk with them about the bad examples of Cain, Ishmael, Esau, and Absalom in relation to their brothers (Jacobus Koelman, The Duties of Parents, 77).