Titus Livius (Livy), The History of Rome, Book 23
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

47. When this was reported to Asellus in the camp, he waited only to ask the consul whether he might fight out of the ranks against an enemy who [p. 161]challenged him. [2] With the consul's permission he at¹ once took up his arms, and riding out in front of the guard-posts he addressed Taurea by name and bade him engage wherever he pleased. [3] Already the Romans had gone out in crowds to that spectacle of a combat, and the Campanians who looked on had filled not only the earthwork of the camp but also the walls of the city. First calling attention to the affair by high-spirited words, they levelled spears and spurred their horses. [4] Then, dodging each other in the open space, they prolonged the bloodless fray. [5] Then the Campanian said to the Roman: “This will be a contest of horses, not of horsemen, unless we let our horses go down from the open field into this deep-cut road. There, with no room to avoid each other, we shall fight hand to hand.” Almost sooner than said Claudius put his horse into the road. [6] Taurea, more spirited in words than in action, said: “Never a nag, please, into a ditch!”² —words which have come down from that time as a farmer's parable. [7] Claudius rode a long way on that road, and then riding back to the field without meeting any enemy, returned as victor to the camp, reviling the cowardice of his enemy in the midst of great rejoicing and congratulations. [8] To this combat of horsemen some annals add what is certainly marvellous —how true, it is for everyone to judge —that, as Claudius was pursuing Taurea fleeing to the city, he rode in through the enemy's open gate and, while they were spellbound in amazement, escaped unharmed by the opposite gate.

[p. 163]