Pliny the Younger (A.D. 62?c.A.D. 113). Letters. The Harvard Classics. 190914.
LXXXIV. Trajan to Pliny
I AGREE with you, my dearest Secundus, in your construction, and am of opinion that the law of Pompey is so far repealed by the edict of the emperor Augustus that those persons who are not less than twenty-two years of age may execute the office of magistrates, and, when they have, may be received into the senate of their respective cities. But I think that they who are under thirty years of age, and have not discharged the function of a magistrate, cannot, upon pretence that in point of years they were competent to the office, legally be elected into the senate of their several communities.