John Calvin Commentary 2 Corinthians 11:10

"As the truth of Christ is in me, no man shall stop me of this glorying in the regions of Achaia." — 2 Corinthians 11:10 (ASV)

The truth of Christ is in me. Lest anyone should suspect that Paul’s words were designed to induce the Corinthians to be more liberal to him in future, and endeavor to make amends for their error in the past, he affirms with an oath that he would take nothing from them, or from others in Achaia, even if it were offered to him. For this manner of expression — the truth of Christ is in me, is in the form of an oath. Let me not be thought to have the truth of Christ in me if I do not retain this glorying among the inhabitants of Achaia. Now Corinth was in Achaia.