John 9:20-21
“We know that this is our son, and that he was born blind; but by what means he now sees we know not, or who has opened his eyes we know not; he is of age, he shall speak for himself.”
By making him to be worthy of credit, they begged off themselves; “He is not a child, say they, nor incapable, but able to testify for himself.”
Source: Homilies on the Gospel of John (New Advent)