Titus Livius (Livy), The History of Rome, Book 10
Rev. Canon Roberts, Ed.

38. The year following was marked by the consulship of L. Papirius Cursor, who had not only inherited his father's glory but enhanced it by his management of a great war and a victory over the Samnites, second only to the one which his father had won. [2] It happened that this nation had taken the same care and pains to adorn their soldiery with all the wealth of splendour as they had done on the occasion of the elder Papirius' victory. They had also called in the aid of the gods by submitting the soldiers to a kind of initiation into an ancient form of oath. [3] A levy was conducted throughout Samnium under a novel regulation; any man within the military age who had not assembled on the captain-general's proclamation, or any one who [4??] had departed without permission, was devoted to Jupiter ¹ and his life [5] forfeited. The whole of the army was summoned to Aquilonia, and 40,000 men, the full strength of Samnium, were concentrated there.

A space, about 200 feet square, almost in the centre of their camp, was boarded off and covered all over with linen [6] cloth. In this enclosure a sacrificial service was conducted, the words being read from an old linen book by an aged priest, Ovius Paccius, who announced that he was taking that form of service from the old ritual of the Samnite religion. It was the form which their ancestors used when they formed their secret design of wresting Capua from the [7] Etruscans. When the sacrifice was completed the captain-general sent a messenger to summon all those who were of noble birth or who were distinguished for their military [8] achievements. They were admitted into the enclosure one by one. As each was admitted he was led up to the altar, more like a victim than like one who was taking part in the service, [9??] and he was bound on oath not to divulge what he saw and heard in that place. Then they compelled him to take an oath couched in the most terrible language, imprecating a [10??] curse on himself, his family, and his race if he did not go into battle where the commanders should lead him or if he either himself fled from battle or did not at once slay any one whom he saw [11] fleeing. At first there were some who refused to take this oath; they were massacred beside the altar, and their dead bodies lying amongst the scattered remains of the victims were a plain hint to the rest not to [12] refuse. After the foremost men among the Samnites had been bound by this dread formula, ten were especially named by the captain-general and told each to choose a comrade-in-arms, and these again to choose others until they had made up the number of 16,ooo. These were called the ‘linen legion,’ from the material with which the place where they had been sworn was covered. They were provided with resplendent armour and plumed helmets to distinguish them from the [13] others. The rest of the army consisted of something under 20,000 men, but they were not inferior to the linen legion either in their personal appearance or soldierly qualities or in the excellence of their equipment. This was the number of those in camp at Aquilonia, forming the total strength of Samnium.