[POMPONIUS libro secundo ex uariis lectionibus. ] §1.8.11.prSi quis uiolauerit muros, capite punitur, sicuti si quis transcendet scalis admotis uel alia qualibet ratione.
[POMPONIUS, From Various Readings, book 2] If anyone violates the walls, he is punished capitally, just as if someone should climb over them by applying ladders or by any other means.
nam ciues Romanos alia quam per portas egredi non licet, cum illud hostile et abominandum sit: nam et Romuli frater Remus occisus traditur ob id, quod murum transcendere uoluerit.
For Roman citizens are not allowed to go out other than through the gates, since that is hostile and abominable; indeed, even Remus, the brother of Romulus, is said to have been killed for the reason that he wished to climb over the wall.