Suetonius, Lives of the Grammarians 24
“Marcus Valerius Probus from Berytus tried to become a centurion for a while and then dedicated himself to study because of the waiting. He had read certain old books with his teacher in the provinces, since the memory of the ancient authors persists there and has not been completely lost as in Rome. Once he returned to these authors more carefully and then wanted to study others, he still pursued this plan even though he knew that everyone had contempt for them and those who studied them earned reproach instead of honor.
Once he obtained many copies, he took care to emend them, edit them, and provide notes for them and he committed himself to this beyond all other aspects of scholarship. Instead of students he had a few followers, for he did not teach in such away as to maintain the façade of a teacher. He used to welcome one or two, or sometimes three or four, in the afternoon hours and while reclining he could occasionally read some things among long and colloquial conversations. He published small number of short works on various minor little questions. But he also left a non insubstantial “Forest of Reflections on the Ancient Language.”
XXIV. M. Valerius Probus, Berytius, diu centuriatum petiit, donec taedio ad studia se contulit. Legerat in provincia quosdam veteres libellos apud grammatistam, durante adhuc ibi antiquorum memoria, necdum omnino abolita sicut Romae. Hos cum diligentius repeteret atque alios deinceps cognoscere cuperet, quamvis omnes contemni magisque opprobrio legentibus quam gloriae et fructui esse animadverteret, nihilo minus in proposito mansit; multaque exemplaria contracta emendare ac distinguere et annotare curavit, soli huic nec ulli praeterea grammatices parti deditus. Hic non tam discipulos quam sectatores aliquot habuit. Nunquam enim ita docuit ut magistri personam sustineret; unum et alterum, vel cum plurimos tres aut quattuor postmeridianis horis admittere solebat, cubansque inter longos ac vulgares sermones legere quaedam idque perraro. Nimis pauca et exigua de quibusdam minutis quaestiunculis edidit. Reliquit autem non mediocrem “Silvam Observationum Sermonis Antiqui.”