John Calvin Commentary John 4:19

"The woman saith unto him, Sir, I perceive that thou art a prophet." — John 4:19 (ASV)

Sir, I perceive that thou art a Prophet. The fruit of the reproof now becomes evident; for not only does the woman modestly acknowledge her fault, but, being ready and prepared to listen to the doctrine of Christ, which she had formerly disdained, she now desires and requests it of her own accord.

Repentance, therefore, is the commencement of true receptiveness to teaching, as I have already said, and opens the gate for entering into the school of Christ.

Again, the woman teaches us by her example that when we meet with any teacher, we should make use of this opportunity, that we may not be ungrateful to God, who never sends Prophets to us without, as it were, stretching out His hand to invite us to Himself. But we must remember what Paul teaches: that those who have grace given to them to teach well are sent to us by God, for how shall they preach unless they are sent? (Romans 10:15).