Romans 15:23

But now having no more any place in these regions and having these many years a longing to come unto you.

This does not mean that Paul was no more welcomed to preach in the great theater of his long and triumphal labors in the gospel, but that, under the rules Paul had laid down for himself relative to preaching the gospel only where it was not already known, he had used up all of the opportunities of the kind he sought. Therefore, he had projected the mission to Spain, including Rome as a necessary way-station, where he planned to request their aid and assistance. Paul's remark here shows how widely the gospel had been diffused throughout the earth at that time, the marvel being that only a little more than a generation had elapsed since Pentecost. Paul could look at a map of Europe with the conviction that there was not a virgin field left in it, except for Spain.