Romans 15:21 Meaning

19Through mighty signs and wonders, by the power of the Spirit of God; so that from Jerusalem, and round about unto Illyricum, I have fully preached the gospel of Christ.

20Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man's foundation:

21But as it is written, To whom he was not spoken of, they shall see: and they that have not heard shall understand.

22For which cause also I have been much hindered from coming to you.

23But now having no more place in these parts, and having a great desire these many years to come unto you;