John Chrysostom

"Yea, so have I strived to preach the Gospel, not where Christ was named." See here another preeminence; that he had not only preached the Gospel to so many, and persuaded them, but he did not even go to those who had become disciples. So far was he from thrusting himself upon other men's disciples, and from doing this for glory's sake, that he even made it a point to teach those who had not heard. For neither does he say where they were not persuaded, but "where Christ was not even named," which is more. …

Homily on Romans 29 ↗

Theophylact of Ohrid

I not only preached the gospel to these and so many peoples and converted them, but I also did not go to those people to whom the name of Christ had already been proclaimed. So far am I from subjecting other people's disciples to myself and doing this for my own glory. Therefore I wrote to you not out of a desire to gain glory from you, but because I am fulfilling my ministry. …

Commentary on Romans ↗

Thomas Aquinas

Then when he says, and I have so preached, he shows how difficult it is to produce this fruit, for it is difficult to convert those entirely ignorant to the faith. First, therefore, he mentions the difficulty, saying: and I have so preached this Gospel, not, indeed, where Christ was named, i.e., not among those who had heard the name of Christ: people whom I had not known served me (Ps 18:43); behold, you shall call nations that you know not, and nations that knew you not shall run to you (Isa 55:5). …

Commentary on Romans ↗