Gregory the Great
Catena Aurea · Markusevangelium 16
Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen. And he said unto them, Go ye into all the world, and preach the Gospel to every creature. He that believeth and is baptized shall be saved; but he that believed not shall be damned. And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues; They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover.
(ubi sup.) After rebuking the hardness of their hearts, let us hear the words of advice which He speaks. For it goes on: Go ye into all the world, and preach the Gospel to every creature. Every man must be understood by every creature; for man partakes something of every creature; he has existence as have stones, life as trees, feeling as animals, understanding as have Angels. For the Gospel is preached to every creature, because he is taught by it, for whose sake all are created, whom all things are in some way like, and from whom therefore they are not alien. By the name of every creature also every nation of the Gentiles may be meant. For it had been said before, Go not into the way of the Gentiles. (Matt. 10:5) But now it is said, Preach the Gospel to every creature, so that the preaching of the Apostles which was thrust aside by Judæa, might be an assistance to us, since Judæa had haughtily rejected it, thus witnessing to her own damnation.