The moral of the ancients was that a servant was considered as a child of the family, and he was never allowed to feel that he was lower in any way than the members of the family. One cannot commit a greater sin than hurting the feelings of the one who serves us and depends upon our help. Once the Prophet heard his grandson call a servant by his name. On hearing this he at once said to his grandson, "No, child, that is not the right way of addressing eiders. You ought to call him "uncle." It does not matter if he serves us, we are all servants of one another, and we are equal in the sight of God.'