Charles Ellicott Commentary Romans 15:21

"but, as it is written, They shall see, to whom no tidings of him came, And they who have not heard shall understand." — Romans 15:21 (ASV)

To whom . . .—From the LXX. of Isaiah 52:15. The original has reference to the servant of Jehovah, first suffering and then glorified, so that kings should be dumb with astonishment at the change. Here it is applied to the evangelization of distant Gentile nations.