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
His declining the suggestion would probably lead to a breach; his
accepting it would throw his most aristocratic and bravest officer
into the hands of a man more than untrustworthy, who, as every one
knew, played a double game with the Romans and with Jugurtha, and
who seemed almost to have contrived the scheme for the purpose of
obtaining for himself provisional hostages from both sides in the
persons of Jugurtha and Sulla.
But the wish to terminate the war
outweighed every other consideration, and Sulla agreed to undertake
the perilous task which Marius suggested to him. He boldly departed
under the guidance of Volux the son of king Bocchus, nor did his
resolution waver even when his guide led him through the midst of
Jugurtha's camp. He rejected the pusillanimous proposals of flight
that came from his attendants, and marched, with the king's son at
his side, uninjured through the enemy. The daring officer evinced
the same decision in the discussions with the sultan, and induced
him at length seriously to make his choice.