Cassius Dio Cocceianus, Dio's Rome, Volume 2
“ While they were encamped opposite each other the women on the barbarian side after divination forbade the men to engage in any battle before the new moon. For this reason Ariovistus, who already paid great heed to them whenever they took any such action, did not join in conflict with his entire force immediately, although the Romans were challenging him to come out. Instead, he sent out the cavalry together with the foot soldiers assigned to them and did the other side severe injury. ”
