The book is traditionally attributed to John the Apostle,[1] but the precise identity of the author remains a point of academic debate.

Some early manuscripts containing the text of this chapter are among others:[4][a] The Textus Receptus has the words Biblical Greek: το ονομα, romanized: to onoma, the name.

Biblical exegete Heinrich Meyer notes that the definite article (το) does not appear in several of the ancient manuscripts and is "to be deleted".

"[22] The vision of Christ "standing at the door" may be expressive of the near approach, or sudden coming of Christ to judgment (see James 5:9), and his knocking may signify the notice that will be given of it, by some of the immediate forerunners and signs of his coming; which yet will be observed but by a few, such a general sleepiness will have seized all professors of religion; and particularly may intend the midnight cry, which will, in its issue, rouse them all.

[25] The hamburger and cheeseburger wrappers of In-N-Out Burger has the text "REVELATION 3:20", which refers to the verse 20 of this chapter.