The Ignatius Catholic Study Bible New Testament (298 page)

4:5 seven torches:
Represent the Holy Spirit (1:4). • The number seven recalls Zech 4:1-6, where the Spirit keeps the seven flames of the lampstand burning, and also Is 11:2, where the Greek OT enumerates seven gifts of the Spirit given to the Messiah (CCC 1831). 
Back to text.

4:6 four living creatures:
Angels that appear as animals. They symbolize the glory of God expressed in creation, e.g., divine authority (lion), strength (ox), intelligence (man), and swiftness (eagle). • Their animal appearance (4:7) resembles the cherubim seen by Ezekiel (Ezek 1:10; 10:1), and their six wings (4:8) recall the seraphim seen by Isaiah (Is 6:2). • Traditional exegesis connects the four living creatures with the four evangelists. Matthew is the
man
whose Gospel begins with the human genealogy of Jesus; Mark is the roaring
lion
whose Gospel begins with the voice crying out in the wilderness; Luke is the sacrificial
ox
whose Gospel begins in the Temple; and John is the soaring
eagle
whose Gospel begins with the highest mystery of Jesus' divinity (e.g., St. Jerome,
Against Jovinianus
1, 26). • The living creatures also refer to the whole Church. Her courage is seen in the lion, her sacrificial service in the ox, her humility in the man, and her sublimity in the flying eagle (St. Bede,
Explanation of the Apocalypse
4, 6). 
Back to text.

4:8 Holy, holy, holy:
The
Sanctus
as chanted in the heavenly liturgy. • The hymn resembles the song of the Seraphim in Is 6:3, where the threefold repetition of "holy" is a Hebrew way of saying that Yahweh is the holiest of all (superlative degree). 
Back to text.

5:1 scroll:
A covenant document whose written decrees are put into effect in 6:1-17 and 8:1-5. • The scroll is sealed like the prophetic visions of Daniel (Dan 8:26; 12:4) and has writing on both sides like the tablets of the Decalogue (Ex 32:15) and the judgment oracles of Ezekiel (Ezek 2:9-10). Christ qualifies as the executor of the Old Covenant (Rev 5:9) with divine authority to administer its blessings and curses. • The sealed book refers to Sacred Scripture, for it was opened by no one except Christ, whose death, Resurrection, and Ascension opened access to all the mysteries it contained. None but the Lord could reveal the hidden meanings of the sacred word (St. Gregory the Great,
Dialogues
4, 44).
seven seals:
Wax seals prevent access to a rolled-up scroll (Is 29:11). 
Back to text.

5:5 the Lion
 . . .
the Root:
Messianic titles for Jesus I (22:16). • The first is from Gen 49:9, where the Messiah comes from Judah, the tribe symbolized by a "lion". The second is from Is 11:10, where the Messiah appears as the "root" of David's father, Jesse. 
Back to text.

5:6 I saw a Lamb:
John expects to see a Lion (5:5) but turns to see a wounded Lamb. This is the first of 28 times that Christ is depicted as a Lamb in Revelation (CCC 608, 1137).
See note on Rev 5:9-10
.
slain:
Christ forever appears as a sacrificial victim, having taken the scars of his Crucifixion with him into heaven (Jn 20:27). Standing upright, his posture symbolizes his victorious rising from death to life (Rev 1:18).
seven horns
 . . .
seven eyes:
Represent the totality of power (Ps 89:17) and knowledge (Zech 4:10) possessed by Christ. 
Back to text.

5:8 harp:
Traditional accompaniment for liturgical song (Ps 33:2).
bowls full of incense:
The saints in heaven mediate the praises and petitions of the saints on earth (Rev 8:3). The rising smoke of incense is a visible sign of prayers ascending to God (Ps 141:2). 
Back to text.

5:9-10
The Lamb receives the same worship given to
I
the Lord God (4:11), indicating that he, too, is divine (19:10). • The words of the song recall the Exodus, when Yahweh redeemed Israel (Ex 15:13) by the shed blood of paschal lambs (Ex 12:21-27) to be a kingly and priestly nation (Ex 19:6). Here it celebrates the new Exodus accomplished by Christ, the new Passover Lamb, whose blood ransoms all nations from sin and consecrates them to serve him as a royal priesthood (Rev 1:6; 1 Pet 2:9) (CCC 608, 1546). 
Back to text.

5:9 a new song:
New songs are composed and sung every time the Lord acts in a new way to save his people (Ps 33:3; 40:3; 144:9; Is 42:10). This song is new as compared to the old victory song sung by Israel after the first Exodus (Ex 15:1-18) (CCC 2642). 
Back to text.

5:11 myriads of myriads:
Countless angels gather to praise the Lord (Dan 7:10) and the Lamb (Heb 1:6). 
Back to text.

6:1-8:5
The breaking of the seals brings judgment upon the earth, which is stained with the righteous blood of the martyrs (6:11). These judgments parallel the eschatological woes that Jesus warned would lead up to the fall of Jerusalem: wars (6:2; Lk 21:9), international strife (6:4; Lk 21:10), famine (6:6; Lk 21:11), pestilence (6:8; Lk 21:11), persecution (6:9; Lk 21:12), earthquakes (6:12; Lk 21:11), and cosmic disturbances (6:12-14; Lk 21:25-26). History tells of an explosion of warfare, calamities, and upheaval in the years leading up to
A.D.
70 and the final devastation of the city. • Conquest, sword, famine, pestilence, and wild beasts (6:2, 4, 8) are forms of the sevenfold covenant curse stipulated in the Torah (Lev 26:1426). Though devastating, these catastrophes are merely a prelude to the worst judgment of all—the utter devastation of the land of Israel and the dispersion of its survivors (Lev 26:2733). This sevenfold vengeance of Yahweh is also the backdrop for the seven trumpets (Rev 8:6-11:19) and the seven bowls of wrath (Rev 15:1-16:21). 
Back to text.