to which I was appointed a preacher and an apostle (I am telling the truth in Christ, not lying), a teacher of the Gentiles in faith and truth.
I speak the truth in Christ, and lie not - That is, by Christ; or I solemnly appeal to Christ - a form of an oath; notes, Romans 9:1. Paul makes a solemn declaration similar to this in regard to his call to the apostleship, in Galatians 1:20. For the reasons why he did it, see the notes on that verse. It is probable that there were those in Ephesus who denied that he could be an apostle, and hence his solemn declaration affirming it.