John 7:15
“How knows this man letters, having never learned?”
Observest thou how the Evangelist shows here also their marveling to be full of wickedness? For he says not, that they admired the teaching, or that they received the words, but simply that they “marveled.” That is, were thrown into a state of astonishment, and doubted, saying, “Whence has this man these things”? When they ought from this very difficulty to have known that there was nothing merely human in Him. But because they would not confess this, but stopped at wondering only, hear what He says.
Source: Homilies on the Gospel of John (New Advent)