It seems like to me I have asked something like this before. I don’t know if it was on this forum or another. What is the meaning of the beast full of eyes in the apocalyse of John?

D-R Bible, Haydock Commentary:

Rev 4:6

Ver. 6. A sea of glass, like crystal, calm and transparent, and may signify that the saints had passed a boisterous sea of troubles in this world, which is now changed into everlasting tranquillity. — Four living creatures, or animals. Alcazar (p. 364) takes notice of thirty different expositions of these animals. He understands the apostles, bishops, and preachers of the Christian faith: others, four of the chief Angels or celestial spirits. Several others expound them of the four evangelists: yet this was before St. John himself had written his gospel. (Witham) — The extensive sea of glass, here described transparent as crystal, represents what may be called the floor of heaven. Before the throne and round it stand four living creatures, of an extraordinary shape, which denote the four great prophets, Isaias, Jeremias, Ezechiel, and Daniel. Their bodies are described full of eyes, both before and behind, an emblem of their prophetic sight, that penetrates into all ages past, present, and to come. And their being also full of eyes within, indicates that their extensive knowledge arises from an interior divine inspiration. They have each six wings, in the same manner as the seraphim appeared to the prophet Isaias. (Chap. vi. 2.) Some have imagined these four symbolical animals to represent the four evangelists; but we think improperly, as St. John was still living and there present in person. The first animal is here said to resemble a lion, the king of beasts, because the prophet Isaias, represented by it, was descended of the royal race of David. The second animal resembles a calf, and represents the prophet Jeremias in his character of priest; the calf, which was the principal victim in Jewish sacrifices, being on that account the emblem of the priesthood. The third animal, exhibiting Ezechiel, has the countenance of a man; because God, in speaking to that prophet, always addresses him by the name of son of man. The fourth animal, denoting Daniel, resembles a flying eagle, on account of the sublime oracles of this prophet, who soars to the highest objects, and views the succession of all the great empires that were to rise up in the world to the end of time. Probably these four principal prophets are to be understood to represent all the prophets of the old law. (Walmesley)

Here is what the Aquinas Study Bible has

**4:6 **The sea of glass is the angels and the blessed themselves. By sea is signified an immense multitude; by glass, brightness, purity, and tranquility; by crystal, solidity and stability of glory and felicity of blessed and angelic minds. (Arethas of Caesarea) Or, that is, Baptism, which is called the sea, because just as the army of the Egyptians drowned in the sea (Ex. 19:27-28), so the army of sin is drowned in Baptism. (St. Albert the Great) Menochius interprets the sea of glass to signify the empyreal heaven; Joachim thinks that it signifies the Holy Scripture.

in the midst: That is, in the midst of the Church, in which God sits, and He rests, as Judge, as the Gloss says. (St. Albert the Great) That is, for the ordering of the Church, just as the father of a family is in the midst of the family, to coordinate and govern. (St. Thomas Aquinas)

round about: As if to protect the wall encircling the city. Through the doctrine that was written by the Evangelists, which is governed and protected by the Church. (St. Thomas Aquinas)

four living creatures: “Recapitulated in Christ,” these are the ones who take part in the service of the praise of God and the fulfillment of his plan: the heavenly powers, all creation the four living beings. (Catechism of the Catholic Church 1138) For Ezekiel 1:5 says, ‘and out of the midst thereof came the likeness of four living creatures.’ (St. Thomas Aquinas)

full of eyes: That is full of heavenly knowledge, and wholesome point of view. (St. Thomas Aquinas) Before, as much as to the goods to be held, and behind, as much as to the vices to be despised. For Philippians 3:14 says, ‘Forgetting the things that are behind and stretching forth myself to those that are before.’ (Hugh of St. Cher) Or, that, is, Scripture which enlighten the Church. (St. Albert the Great)

4:7 Some commentators understood the 4 living creatures to represent the four Evangelists Matthew, Mark, Luke, and John, and as St. Gregory says, the Evangelists are compared to living creatures, because those animal characteristics symbolize their Gospels and what they wrote. (St. Thomas Aquinas) Primasius understood them as characteristics of the Church. St. Andrew of Caesarea, St. Basil, and Oecumenius understood them as Serephim angels.

St. Augustine
(Characteristics of the Evangelists)

lion: Matthew is intended in the lion, in that he describes the ancestral line of regal dignity in Christ.
ox: Luke is intended in the ox, which was the great victim under the Law.
man: Mark only relates simply the actions of the man Christ.
eagle: John is the eagle for with keen sight he beholds the nativity of the Word, as the risen Sun.

(Characteristics of the Church)
lion: The Church lives and works on the strength and beauty of the royal majesty.
Ox: the first victim, for whenever anyone of the faithful is slain for Christ, he conquers at that moment.
man: the humility of the Church is here commended.
eagle: The celestial Church is being described as flying on the spiritual thoughts of Her members.