And when we came to Rome, the centurion delivered the prisoners to the captain of the guard: but Paul was suffered to dwell by himself with a soldier that kept him. The captain of the guard - Στρατοπεδαρχῃ. This word properly means the commander of a camp; but it signifies the prefect, or commander of the pretorian cohorts, or emperor's guards.
Tacitus (Annal. lib. iv. cap. 2) informs us that, in the reign of Tiberius, Sejanus, who was then prefect of these troops, did, in order to accomplish his ambitious designs, cause them to be assembled from their quarters in the city, and stationed in a fortified camp near it; so that their commander is with peculiar propriety styled by St. Luke στρατοπεδαρχης, the commander of the camp. For the arrival of St. Paul at Rome was in the seventh year of Nero; and it is certain, from Suetonius, (in Tiber. cap. 37), that the custom of keeping the pretorian soldiers in a camp, near the city, was retained by the emperors succeeding Tiberius; for the historian observes that Claudius, at his accession to the empire, was received into the camp, in castra delatus est, namely, of the pretorian cohorts; and so Tacitus says of Nero, An. lib. xii. cap. 69, that on the same occasions illatus castris, he was brought into the camp. Dr. Doddridge observes that it was customary for prisoners who were brought to Rome to be delivered to this officer, who had the charge of the state prisoners, as appears from the instance of Agrippa, who was taken into custody by Macro, the pretorian prefect, who succeeded Sejanus; (Joseph. Ant. lib. xviii. cap. 7. sec. 6); and from Trajan's order to Pliny, when two were in commission, Plin. lib. x. Ephesians 65. Vinctus mitti ad praefectos praetorii mei debet: he should be sent bound to the prefects of my guards. The person who now had that office was the noted Afranius Burrhus; but both before and after him it was held by two: Tacit. An. lib. xii. sec. 42; lib. xiv. sec. 51. See Parkhurst.
Burrhus was a principal instrument in raising Nero to the throne; and had considerable influence in repressing many of the vicious inclinations of that bad prince. With many others, he was put to death by the inhuman Nero. Burrhus is praised by the historians for moderation and love of justice. His treatment of St. Paul is no mean proof of this. Calmet.
With a soldier that kept him - That is, the soldier to whom he was chained, as has been related before, Acts 12:6.