Ambrose of Milan — as excerpted in the Catena Aurea on Luke 2:1-5

“There is described a secular registration, implied a spiritual, to be laid before the King not of earth but of Heaven; a registering of faith: a census of souls. For the old census of the Synagogue was abolished, a new census of the Church was preparing. And to decide that the census was not of Augustus, but of Christ, the whole world is ordered to be registered. For who could demand the registration of the whole world but He who had dominion over it, for the earth is not of Augustus, but the earth is the Lord’s? (Ps. 24:1.)”