The very beautiful and interesting Epistle to Philemon does not require much comment; it is an expression of the love which works by the Spirit within the assembly of God in all the circumstances of individual life.
Written for the purpose of awakening in Philemon sentiments which certain events had a tendency to extinguish in his heart, this epistle is suited to produce those feelings in the reader more than to be the object of explanation.
When the human mind is occupied with elevated subjects, it feels their weight, and bends under the load; it is absorbed; it has to abstract itself, to fix its attention. God reveals His own thoughts; and, vast as they may be to the human mind, they flow with the clearness and connectedness that is natural to them, when he communicates them by His chosen instruments. The latter are free to love; for the God who employs them and inspires them is love. It is a more essential part of their task to present Him thus, than even to speak of the deep things. Accordingly, when they are moved by that love, the character of Him who sends them is demonstrated as that of the God who is the source of love, by a perfect consideration for others, and the most delicate attention to those things which their hearts would feel.
Moreover this love develops itself in relationships formed by the Holy Ghost Himself, between the members of the body of Christ, that is to say, between men. Springing from a divine source, and always fed b y it, Christian affections assume the form of human regard, which by exhibiting love and the opposite of selfishness, bear the stamp of their origin. Love, free from self, can and does think of all that concerns others and understands what will affect them.
Paul at this moment was a prisoner at Rome. God had brought Onesimus there (whither all resorted) to lead him to salvation and the knowledge of the Lord, in order that we should be instructed, and that Onesimus should have a new position in the christian assembly. 
Finally, that which we have especially to remark in the Epistle to Philemon is the love which, in the intimate centre of this circle (guarded all round by an unparalleled development of doctrine) reigned and bore fruit, and bound the members of Christ together, and spread the savour of grace over all the relationships in which men could stand towards each other, occupying itself about all the details of life with a perfect propriety, and with the recognition of every right that can exist among men and of all that the human heart can feel.