Hastings' Dictionary of the Bible (1898)
LIB'ERTINES, mentioned only in Acts 6:9, were Jews who, having been taken prisoners in the Syrian wars, were carried to Rome and reduced to slavery, but afterward emancipated. That their number was considerable is apparent from the fact that 4000 of them were banished from Rome in a.d. 19. In Jerusalem they had a synagogue, and there they came in collision with Stephen.