Revelation 5:3 - Ellicott's Commentary On The Whole Bible

And no man.... — Or, better, no one (for it is of more than mankind that the Apostle speaks) was able, in the heaven, nor on the earth, nor under the earth, nor even (still less?) to look thereon. The looking on the book is usually understood of the look cast on the book of one who would read the contents. If so, the thought is, none could open, still less read, the roll. It may, however, be that all who attempted to take the book were unable to face the glory in which it lay. When Christ revealed Himself to Saul he could not see for the glory of that light.