2 Corinthians 8:18

And who is this brother? Some indeed say, Luke, because of the history which he wrote, but some, Barnabas; for he calls the unwritten preaching also Gospel. And for what cause does he not mention their names; whilst he both makes Titus known by name, and praises him for his cooperation in the Gospel, (seeing that he was so useful that by reason of his absence even Paul could do nothing great and noble; for, "because I found not Titus my brother, I had no relief for my spirit,") and for his love towards them, (for, saith he, "his inward affection is more abundant towards you;") and for his zeal in this matter ("for," he saith, "of his own accord he went")? But these he neither equally commends, nor mentions by name? What then is one to say? Perhaps they did not know them; wherefore he does not dwell upon their praises because as yet they had had no experience of them, but only says so much as was sufficient for their commendation unto them (i.e. the Corinthians,) and to their escaping all evil suspicion. However, let us see on what score he eulogizes this man himself also. On what score then does he eulogize? First, praising him from his preaching; that he not only preached, but also as he ought, and with the befitting earnestness. For he said not, 'he preaches and proclaims the Gospel,' but, "whose praise is in the Gospel." And that he may not seem to flatter him, he brings not one or two or three men, but whole Churches to testify to him, saying, "through all the churches." Then he makes him respected also from the judgment of those that had chosen him. And this too is no light matter.