The angel's cry is a public challenge to all creation. The book is in God's own hand, and opening it takes more than strength. Barnes says the angel speaks "as a herald or crier," and that "worthy" means "having a rank so exalted, and attributes so comprehensive, as to authorize and enable him to do it." Gill says the proclamation was made "to show the impotence of all creatures," so that the worth of Jesus Christ would stand out.

At first, no one: "no man in heaven, nor in earth, neither under the earth, was able to open the book, neither to look thereon" (Revelation 5:3). John says, "I wept much" (Revelation 5:4). Then one of the elders tells him, "Weep not: behold, the Lion of the tribe of Juda, the Root of David, hath prevailed to open the book" (Revelation 5:5). John turns and sees "a Lamb as it had been slain" (Revelation 5:6), who takes the book (Revelation 5:7). Heaven answers the angel's question in song: "Thou art worthy to take the book, and to open the seals thereof: for thou wast slain" (Revelation 5:9).

The "book" is a scroll, the usual form of a book in John's day. This one is written on both sides and closed with seven seals, so no one can read it until the seals are broken. Barnes suggests it "seems to have been" held so that John could see distinctly how it was written and sealed.

Commentators describe what the scroll holds in slightly different ways. Gill, after weighing other readings, concludes that "the book of God's decrees is here meant." Matthew Henry speaks of God's plans for "the church and the world" being fixed, "as that which is written in a book." Both agree it holds what God has purposed, and only the worthy One can open it. Gill adds that the angel is "a created one," and that who exactly he was "is not material to be known."

This question shows that what God holds in His own hand, His purposes (as Gill and Matthew Henry both describe the book), is opened only through the Lamb. No one in heaven, on earth, or under the earth could open it (Revelation 5:3). Matthew Henry says the One worthy to open "all the counsels of God towards men" is the Mediator, "God and man." The answer comes in a surprising form: John hears of a Lion, but sees a Lamb that had been slain (Revelation 5:5-6). His worthiness rests on His sacrifice: "for thou wast slain, and hast redeemed us to God by thy blood" (Revelation 5:9).

The question that brought John to tears ends in worship from every creature (Revelation 5:13). Henry observes that "Those who have seen most of God in this world are most desirous to see more." John's tears were not unbelief. They were longing, and God answered that longing with the Lamb.