For this cause. The reference is not merely to the last statement or illustration, but to the whole view of the purpose of God toward the Gentiles unfolded in Ephesians it. The apodosis does not come in till verse 14, at the beginning of which this conjunctive clause is repeated.
I Paul, the prisoner of Christ Jesus for you Gentiles. He introduces himself in order to make known the feelings which were roused in his soul towards them by the consideration of the privileges just enlarged on—especially to acquaint them with the prayers he offered for them (see verses 14-19), and apparently with the indirect object of getting them to offer similar prayers for themselves.
To justify this introduction of himself, he delicately introduces the fact of his being a prisoner on their behalf. What had brought him to Rome, what had made him appeal to Caesar, was his preaching the gospel to the Gentiles; indeed, the immediate occasion of his arrest at Jerusalem was the suspicion that he had taken Trophimus, an Ephesian, one of themselves, into the temple (Acts 21:29).
By this allusion to the condition into which his regard for them had brought him, be conciliates sympathetic consideration of what is to follow.