And I saw when the Lamb opened one of the seals, and I heard, as it were the noise of thunder, one of the four beasts saying, Come and see. When the Lamb opened one of the seals - It is worthy of remark that the opening of the seals is not merely a declaration of what God will do, but is the exhibition of a purpose then accomplished; for whenever the seal is opened, the sentence appears to be executed. It is supposed that, from Revelation 6:1-11, the calamities which should fall on the enemies of Christianity, and particularly the Jews, are pointed out under various images, as well as the preservation of the Christians under those calamities.
One of the four beasts - Probably that with the face of a lion. See Revelation 4:7.
Come and see - Attend to what is about to be exhibited. It is very likely that all was exhibited before his eyes as in a scene, and he saw every act represented which was to take place, and all the persons and things which were to be the chief actors.