Just to appraise the value of Irenaeus testimony, a few paragraphs earlier he is insistent that Jesus was 50 years old. Arguing passionately that the Apostles taught this. Reality is, the traditions were all in flux yet.
On completing His thirtieth year He suffered, being in fact still a young man, and who had by no means attained to advanced age. Now, that the first 392stage of early life embraces thirty years,3140 and that this extends onwards to the fortieth year, every one will admit; but from the fortieth and fiftieth year a man begins to decline towards old age, which our Lord possessed while He still fulfilled the office of a Teacher, even as the Gospel and all the elders testify; those who were conversant in Asia with John, the disciple of the Lord, [affirming] that John conveyed to them that information.3141 And he remained among them up to the times of Trajan.3142 Some of them, moreover, saw not only John, but the other apostles also, and heard the very same account from them, and bear testimony as to the [validity of] the statement. Whom then should we rather believe? Whether such men as these, or Ptolemæus, who never saw the apostles, and who never even in his dreams attained to the slightest trace of an apostle?