John Calvin Commentary 2 Corinthians 6:11

"Our mouth is open unto you, O Corinthians, our heart is enlarged." — 2 Corinthians 6:11 (ASV)

Our mouth is opened. As the opening of the mouth is a sign of boldness, if you are inclined to connect this with what precedes, the meaning will be this: “I have ample ground for glorying, and an upright conscience opens my mouth. The unfavorable views you hold of us are not due to any fault on our part, but arise from your being unfair judges. For you should have held more favorable views of my ministry, which God has made honorable to you in so many ways.”

However, I explain it differently. For he says that the reason his mouth was opened was that his heart was enlarged.

Now, what is meant by enlargement of heart? It undoubtedly means the cheerfulness that springs from benevolence. It is quite a common figure to speak of a narrow and contracted heart as denoting either grief, or disgust, while, on the other hand, an enlarged heart is used to denote dispositions of an opposite kind.

Therefore, Paul here says nothing but what we experience every day. For when we are with friends, our heart is enlarged, all our feelings are laid open, there is nothing hidden there, nothing shut—indeed, the whole mind leaps and exults to unfold itself openly to view.

This is why the tongue, also, is free and unfettered, does not falter, and does not with difficulty draw up broken syllables from the bottom of the throat, as usually happens when the mind is influenced by a less joyful emotion.