I have then, etc. After having in general commended his own calling, that the Romans might know that he was a true and undoubted apostle of Christ, he now adds testimonies, by which he proved that he had not only taken upon him the apostolic office conferred on him by God's appointment, but that he had also eminently adorned it. He at the same time records the fidelity which he had exhibited in discharging his office. It is indeed to little purpose that we are appointed, except we act agreeably to our calling and fulfill our office. He did not make this declaration from a desire to attain glow, but because nothing was to be omitted which might procure favor and authority to his doctrine among the Romans. In God then, not in himself, did he glory; for he had nothing else in view but that the whole praise should redound to God. And that he speaks only negatively, it is indeed an evidence of his modesty, but it availed also to gain credit to what he was proceeding to announce, as though he said, "The truth itself affords me such cause for glowing, that I have no need to seek false praises, or those of another, I am content with such as are true." It may be also that he intended to obviate the unfavorable reports which he knew were everywhere scattered by the malevolent, he therefore mentioned beforehand that he would not speak but of things well known.

I have therefore - I have cause of glorying. I have cause of rejoicing that God has made me a minister to the Gentiles, and that he has given me such success among them. The ground of this he states in Romans 15:18-22.
Glory - Of "boasting" καύχησιν kauchēsin, the word usually rendered "boasting"); James 4:16; Romans 3:27; 2-Corinthians 7:14; 2-Corinthians 8:24; 2-Corinthians 9:3-4; 2-Corinthians 10:15; 2-Corinthians 11:10, 2-Corinthians 11:17. It means also "praise, thanksgiving," and "joy;" 1-Corinthians 15:31; 2-Corinthians 1:12; 2-Corinthians 7:4; 2-Corinthians 8:24; 1-Thessalonians 2:19. This is its meaning here, that the apostle had great cause of "rejoicing" or "praise" that he had been so highly honored in the appointment to this office, and in his success in it.
Through Jesus Christ - By the assistance of Jesus Christ; ascribing his success among the Gentiles to the aid which Jesus Christ had rendered him.
In those things which pertain to God - Compare Hebrews 5:1. The things of religion; the things which God has commanded, and which pertain to his honor and glory. They were not things which pertained to "Paul," but to "God:" not worked by Paul, but by Jesus Christ; yet he might rejoice that he had been the means of diffusing so far those blessings. The success of a minister is not for "his own" praises, but for the honor of God; not by his skill or power, but by the aid of Jesus Christ; yet he may rejoice that "through" him such blessings are conferred upon people.

I here therefore whereof I may glory - Being sent of God on this most honorable and important errand, I have matter of great exultation, not only in the honor which he has conferred upon me, but in the great success with which he has crowned my ministry.

(9) I have therefore whereof I may glory through Jesus Christ in those things which pertain to God.
(9) He commends his apostleship highly by the effects, but yet in such a way that even though he speaks all things truly, he gives all the glory to God as the only author: and he does not do this for his own sake, but this rather, that men might doubt less of the truth of the doctrine which he propounds to them.

I have therefore whereof I may glory,.... Not in himself, for he that taught others not to glory in men, would not glory in himself; not in his carnal descent and fleshly privileges; nor in his knowledge of, and compliance with, the ceremonies of the law; nor in his legal, moral, and civil righteousness before God; nor in his gifts and attainments, as merited and procured by himself; nor in his labours in the ministry, and the success of it, as of himself: but
through Jesus Christ; or "in Jesus Christ", as read the Vulgate Latin, Syriac, and Arabic versions; in what Christ was unto him, wisdom, righteousness, sanctification, and redemption: he could boast of what he had from him, and through him, even of all spiritual blessings in him; and of a large measure of grace he had received from him; and of great and eminent gifts Christ had bestowed on him; he gloried in his cross, and boasted of a crucified Jesus, whom others despised; and whom he made the subject of his ministry, and took delight in preaching: and freely owned that all he did was through Christ strengthening him; and that all his success in his work was owing to him, and of this he had to glory: and which was
in those things which pertain to God; not "with God", as the Syriac reads it; for though in some cases it may be lawful to glory before men, yet not before God, or in his presence: nor is it anything a man may glory in, not in his own things, but in the things of God; in things relating to the Gospel of God, to the pure preaching of it, to the furtherance and spread of it, and the recommending of it to others; to the worship and ordinances of God, and a spiritual attendance on them; to the grace of God, and the magnifying of that in the business of salvation; and to the glory of God, which ought to be the chief end of all actions, natural, moral, and religious, and whether private or public. The apostle has chiefly reference to his ministerial function, and the things of God relating to that, in which he was employed; see Hebrews 5:1.

I have therefore whereof I may glory--or (adding the article, as the reading seems to be), "I have my glorying."
through--"in"
Christ Jesus in those things which pertain to God--the things of the ministry committed to me of God.

I have therefore whereof I may glory. Because of his wonderfully successful ministry among the Gentiles. Yet he glories not in himself, but only through Jesus Christ. See 1-Corinthians 15:31.
In those things which pertain to God. In his ministry as an apostle of Christ.
I will not dare to speak, etc. The meaning is: "I will not dare to speak of the signs of grace and the work of others, but only of the mighty works of God hath wrought through me to make the Gentiles obedient."
Through mighty signs and wonders. This describes what extraordinary help had been given--the power to work miracles and the gifts of the Holy Spirit.
So that from Jerusalem, and around about unto Illyricum. Jerusalem was near the southeast corner of the Mediterranean; Illyricum lay north of Greece, on the Adriatic, so that his gospel labors had embraced a circuit clear around the east and northeast shores of the sea.
Yea, so have I strived to preach. He declares the fixed policy of his ministry not to preach where Christ had been heard, but in new fields. Where other apostles or evangelists had laid a foundation, he did not seek to build. Compare 2-Corinthians 10:12-16. As no apostle or great evangelist had yet visited Rome, his letter to the Romans was no violation of his principle.
But as it is written. In Isaiah 52:15. The passage declares that God's name shall be carried where it was unknown; hence, Paul's course was in harmony with the will of God.

I have whereof to glory through Jesus Christ - All my glorying is in and through him.