Titus Livius (Livy), The History of Rome, Book 22
Benjamin Oliver Foster, Ph.D., Ed.

41. But even Fortune furnished material to the recklessness and over-hasty temper of the consul.¹ The repulse of a foraging party had led to a general mellay, which came about from the soldiers rushing forward to attack the enemy, rather than from any plan or orders on the part of the generals; and in this the Phoenicians by no means held their own. [2] About seventeen hundred of them were slain and not more than a hundred of Romans and allies. But the consul Paulus, who was in command that day —for they commanded on alternate days —was [3] fearful of an ambuscade and checked the victors in their headlong pursuit, despite the angry remonstrances of Varro, who cried out that they had let the enemy slip through their hands and that they might have brought the war to a conclusion if they had not relaxed their efforts.

[4] Hannibal was not greatly disconcerted by this reverse; indeed he rejoiced that the hook should have been baited, as it were, for the rashness of the more impetuous consul, and especially for that of the new soldiers. [5] All the circumstances of his enemies were as familiar to him as his own: that their generals were unlike each other and were at loggerheads, and that nearly two-thirds of their army consisted of recruits. [6] Believing, therefore, that place and time were favourable for a ruse, he left his camp full of every sort of public and of private riches, and putting himself at the head of his troops, who carried nothing but their weapons, marched over the nearest [p. 339]ridge, drew up the [7??] infantry in ambush on the left,² and the cavalry on the right, and made the baggage-train pass through the valley between, intending to fall upon [8??] the enemy whilst they were preoccupied and encumbered with the pillage of the camp, which would seem to them to have been deserted by its owners. [9] He left a large number of fires burning, as though he had sought by means of this illusory appearance of an encampment to hold the consuls to their positions —as he had cheated Fabius the year before —till he could gain as long a start as possible in his retreat.