Romans 15:29

29.And I know, that when I come, etc. These words may be explained in two ways: the first meaning is, — that he should find a plentiful fruit from the gospel at Rome; for the blessing of the gospel is, when it fructifies by good works: but to confine this to alms, as some do, is not what I approve. The second is, that in order to render his coming to them more an object of desire, he says, that he hopes that it would not be unfruitful, but that it would make a great accession to the gospel; and this he calls fullness of blessing, which signifies a full blessing; by which expression he means great success and increase. But this blessing depended partly on his ministry and partly on their faith. Hence he promises, that his coming to them would not be in vain, as he would not disappoint them of the grace given to him, but would bestow it with the same alacrity with which their minds were prepared to receive the gospel.

The former exposition has been most commonly received, and seems also to me the best; that is, that he hoped that at his coming he would find what he especially wished, even that the gospel flourished among them and prevailed with evident success, — that they were excelling in holiness and in all other virtues. For the reason he gives for his desire is, that he hoped for no common joy in seeing them, as he expected to see them abounding in all the spiritual riches of the gospel. (463)