Ambrosiaster : Paul is saying this because of the freedom he enjoyed in a pure conscience. A mind with a bad conscience is afraid to speak, loses its train of thought and makes verbal slips. People whose heart is enlarged are happy with themselves because they are confident that they have behaved well. — COMMENTARY ON PAUL'S EPISTLES John Chrysostom : "Our mouth is open unto you, O ye Corinthians." And what kind of sign of love is this? or what meaning even have the words at all? 'We cannot endured' he says, 'to be silent towards you, but are always desiring and longing to speak to and converse with you;' which is the wont of those who love. For what grasping of the hands is to the body, that is interchange of language to the soul. And along with this he implies another thing also. Of what kind then is this? That 'we discourse unto nothing.' For since afterwards he proposes to rebuke, he asks forgiveness, using the rebuking them with freedom as itself a proof of his loving them exceedingly. Moreover the addition of their name is a mark of great love and warmth and affection; for we are accustomed to be repeating continually the bare names of those we love. "Our heart is enlarged." For as that which warmeth is wont to dilate; so also to enlarge is the work of love. For virtue is warm and fervent. This both opened the mouth of Paul and enlarged his heart. For, 'neither do I love with the mouth only,' saith he, 'but I have also a heart in union. Therefore I speak with openness, with my whole mouth, with my whole mind.' For nothing is wider than was Paul's heart which loved all the faithful with all the vehemence that one might bear towards the object of his affection; this his love not being full entireness with each. — Homily 13 on 2 Corinthians