Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
Hannibal in Gaul - Scipio at Massilia - Passage of the Rhone
Arrived at the Pyrenees, Hannibal sent home a portion of his troops;
a measure which he had resolved on from the first with the view of
showing to the soldiers how confident their general was of success,
and of checking the feeling that his enterprise was one of those from
which there is no return home.
With an army of 50,000 infantry and
9000 cavalry, entirely veteran soldiers, he crossed the Pyrenees
without difficulty, and then took the coast route by Narbonne and
Nimes through the Celtic territory, which was opened to the army
partly by the connections previously formed, partly by Carthaginian
gold, partly by arms. It was not till it arrived in the end of July
at the Rhone opposite Avignon, that a serious resistance appeared to
await it.
The consul Scipio, who on his voyage to Spain had landed at
Massilia (about the end of June), had there been informed that he had
come too late and that Hannibal had crossed not only the Ebro but the
Pyrenees.