Verse 2. And I saw a strong angel. An angel endowed with great strength, as if such strength was necessary to enable him to give utterance to the loud voice of the inquiry. "Homer represents his heralds as powerful, robust men, in order consistently to attribute to them deep-toned and powerful voices." -- Professor Stuart. The inquiry to be made was one of vast importance; it was to be made of all in heaven, all on the earth, and all under the earth, and hence an angel is introduced so mighty that his voice could be heard in all those distant worlds.

Proclaiming with a loud voice. That is, as a herald or crier. He is rather introduced here as appointed to this office than as self-moved. The design undoubtedly is to impress the mind with a sense of the importance of the disclosures about to be made, and at the same time with a sense of the impossibility of penetrating the future by any created power. That one of the highest angels should make such a proclamation would sufficiently show its importance; that such an one, by the mere act of making such a proclamation, should practically confess his own inability, and consequently the inability of all of similar rank, to make the disclosures, would show that the revelations of the future were beyond mere created power.

Who is worthy to open the book, etc. That is, who is "worthy" in the sense of having a rank so exalted, and attributes so comprehensive, as to authorize and enable him to do it. In other words, who has the requisite endowments of all kinds to enable him to do it? It would require moral qualities of an exalted character to justify him in approaching the seat of the holy God to take the book from his hands; it would require an ability beyond that of any created being to penetrate the future, and disclose the meaning of the symbols which were employed. The fact that the book was held in the hand of him that was on the throne, and sealed in this manner, was in itself a sufficient proof that it was not his purpose to make the disclosure directly, and the natural inquiry arose whether there was any one in the wide universe who, by rank, or character, or office, would be empowered to open the mysterious volume.