Wherefore, though I might be much bold - It would be better to read: Wherefore, although I have much authority through Christ, to command thee to do what is proper; yet, on account of my love to thee, I entreat thee.
The tenderness and delicacy of this epistle, says Dr. Paley, have long been admired: "Though I might be much bold in Christ to enjoin thee that which is convenient; yet, for love's sake, I rather beseech thee, being such a one as Paul the aged, and now also a prisoner of Christ Jesus, I beseech thee for my son Onesimus, whom I have begotten in my bonds."
There is something certainly very melting and persuasive in this and every part of the epistle. Yet, in my opinion, the character of St. Paul prevails in it throughout. The warm, affectionate, authoritative teacher is interceding with an absent friend for a beloved convert. He urges his suit with an earnestness befitting, perhaps, not so much the occasion as the ardour and sensibility of his own mind. Here also, as everywhere, he shows himself conscious of the weight and dignity of his mission; nor does he suffer Philemon, for a moment, to forget it: "I might be much bold in Christ, to enjoin thee that which is convenient." He is careful also to recall, though obliquely, to Philemon's memory, the sacred obligation under which he had laid him, by bringing him to the knowledge of Christ: "I do not say to thee, how thou owest to me even thine own self besides." Without laying aside, therefore, the apostolic character, our author softens the imperative style of his address, by mixing with it every sentiment and consideration that could move the heart of his correspondent. Aged, and in prison, he is content to supplicate and entreat. Onesimus was rendered dear to him by his conversation and his services; the child of his affliction, and "ministering unto him in the bonds of the Gospel." This ought to recommend him, whatever had been his fault, to Philemon's forgiveness: "Receive him as myself, as my own bowels." Every thing, however, should be voluntary. St. Paul was determined that Philemon's compliance should flow from his own bounty; "Without thy mind would I do nothing, that thy benefit should not be as it were of necessity, but willingly;" trusting, nevertheless, to his gratitude and attachment for the performance of all that he requested, and for more: "Having confidence in thy obedience, I wrote unto thee, knowing that thou wilt also do more than I say." St. Paul's discourse at Miletus; his speech before Agrippa; his Epistle to the Romans; that to the Galatians, Galatians 4:11-20; to the Philippians, Philemon 1:29; Philemon 2:2; the second to the Corinthians, 2 Corinthians 6:1-13; and indeed some part or other of almost every epistle, exhibit examples of a similar application to the feelings and affections of the persons whom he addresses. And it is observable that these pathetic effusions, drawn for the most part from his own sufferings and situation, usually precede a command, soften a rebuke, or mitigate the harshness of some disagreeable truth. Horae Paulinae, p. 334.
Wherefore, though I might be much bold in Christ - Though I might have much boldness as an apostle of Christ. He means that he was invested with authority by the Lord Jesus, and would have a right, as an apostle, to enjoin what ought to be done in the case which he is about to lay before him; compare 1 Thessalonians 2:6-7.
To enjoin thee that which is convenient - To command what is proper to be done. The word “convenient” here ( τὸ ἀνῆκω to anēkō), means that which would be fit or proper in the case; compare the notes at Ephesians 5:4. The apostle implies here that what he was about to ask, was proper to be done in the circumstances, but he does not put it on that ground, but rather asks it as a personal layout. It is usually not best to command a thing to be done if we can as well secure it by asking it as a favor; compare Daniel 1:8, Daniel 1:11-12.