Laudator Temporis Acti

Livy 10.38.5-12 (293 BC; tr. B.O. Foster):

[5] There, at about the middle of the camp, they had enclosed an area, extending approximately two hundred feet in all directions, with wicker hurdles, and roofed it over with linen. [6] In this place they offered sacrifice in accordance with directions read3 from an old linen roll. The celebrant was one Ovius Paccius, an aged man, who claimed to derive this ceremony from an ancient ritual of the Samnites which the forefathers of those present had formerly employed when they had gone secretly about to get Capua away from the Etruscans. [7] On the conclusion of the sacrifice, the general by his apparitor commanded to be summoned all those of the highest degree in birth and deeds of arms; and one by one they were introduced. [8] Besides other ceremonial preparations, such as might avail to strike the mind with religious awe, there was a place all enclosed, with altars in the midst and slaughtered victims lying about, and round them a guard of centurions with drawn swords. [9] The man was brought up to the altar, more like a victim than a partaker in the rite, and was sworn not to divulge what he should there see or hear. [10] They then compelled him to take an oath in accordance with a certain dreadful form of words, whereby he invoked a curse upon his head, his household, and his family, if he went not into battle where his generals led the way, or if he either fled from the line himself or saw any other fleeing and did not instantly cut him down. [11] Some there were at first who refused to take this oath; these were beheaded before the altars, where they lay amongst the slaughtered victims — a warning to the rest not to refuse. [12] When the leading Samnites had been bound by this imprecation, the general named ten of them and bade them choose every man another, and so to proceed until they had brought their number up to sixteen thousand. These were named the "Linen Legion," from the roof of the enclosure wherein the nobles had been sworn, and were given splendid arms and crested helmets, to distinguish them from the rest.

[5] ibi mediis fere castris locus est consaeptus cratibus pluteisque et linteis contectus, patens ducentos maxime pedes in omnes pariter partes. [6] ibi ex libro vetere linteo lecto sacrificatum sacerdote Ovio Paccio quodam, homine magno natu, qui se id sacrum petere adfirmabat ex vetusta Samnitium religione, qua quondam usi maiores eorum fuissent cum adimendae Etruscis Capuae clandestinum cepissent consilium. [7] sacrificio perfecto per viatorem imperator acciri iubebat nobilissimum quemque genere factisque: [8] singuli introducebantur. erat cum alius apparatus sacri qui perfundere religione animum posset, tum in loco circa omni contecto arae in medio victimaeque circa caesae et circumstantes centuriones strictis gladiis. [9] admovebatur altaribus magis ut victima quam ut sacri particeps adigebaturque iure iurando quae visa auditaque in eo loco essent, non enuntiaturum. [10] dein iurare cogebant diro quodam carmine, in exsecrationem capitis familiaeque et stirpis composito, nisi isset in proelium quo imperatores duxissent et si aut ipse ex acie fugisset aut si quem fugientem vidisset non extemplo occidisset. [11] id primo quidam abnuentes iuraturos se obtruncati circa altaria sunt; iacentes deinde inter stragem victimarum documento ceteris fuere ne abnuerent. [12] primoribus Samnitium ea detestatione obstrictis, decem nominatis ab imperatore, eis dictum, ut vir virum legerent donec sedecim milium numerum confecissent. ea legio linteata ab integumento consaepti, in quo sacrata nobilitas erat, appellata est: his arma insignia data et cristatae galeae, ut inter ceteros eminerent.

I don't understand why Foster in section 7 translated viatorem by another Latin word (apparitor). I would translate it as agent — see Oxford Latin Dictionary, s.v. uiator, sense 2.