Revelation 4:6

The sea of glass refers to baptism, where "it is believed with the heart unto justification, and there is confession with the mouth unto salvation." And it is likened to glass because of faith. For in glass there is nothing to be seen on the …

The sea of glass is like crystal, that is, it is transparent, indicating that it is infused by a certain whiteness and an uncommon purity. With good reason we think that this is said of the font of baptism and of the grace of regeneration. …

"And before the throne there was, as it were, a sea of glass like to crystal." That is the gift of baptism which He sheds forth through His Son in time of repentance, before He executes judgment. It is therefore before the throne, that is, the judgment.And when he says a sea of glass like to crystal, he shows that it is pure water, smooth, not agitated by the wind, not flowing down as on a slope, but given to be immoveable as the house of God."And round about the throne were four living creatures." The four living creatures are the four Gospels.

And from the throne proceeded lightnings, and voices, and thunders. Here it is clearly shown that the throne symbolizes the Church, which all these things tally with. For by lightnings we understand miraculous signs; whence the Psalmist: Thy lightnings enlightened the world, [Ps. 76:19] and …

And in the midst of the throne and around the throne, there were four living creatures, full of eyes in front and behind. All parts of the throne of God, that is, the Church, are filled with the light of the Gospel from the knowledge …

And before the throne, there was as it were a sea of glass, like crystal. This refers to the faith of true baptism, which is related to glass, in which nothing different is seen on the outside than what it bears within. The grace of …

And before the throne there was a sea of glass like unto crystal,.... By which is meant, not heaven, nor the souls of the blessed there, nor the multitude of the holy angels, nor the first converts to Christianity at Jerusalem; for those that got the victory over the beast are said to stand upon this sea, Rev 15:2, which these senses, especially the three last, will by no means admit of.

As in the temple there was a great vessel of brass filled with water, in which the priests were to wash when they went to minister before the Lord (and this was called a sea ), so in the gospel church the sea or laver for purification is the blood of the Lord Jesus Christ, who cleanses from all sin, even from sanctuary-sins.

Their number, also, is symbolical of universality, and agrees with the dispensation of the gospel, which extended to all nations under heaven. And the "new song" which they all sing, saying, "Thou hast redeemed us out of every kindred, and tongue, and people, and nation," chap. v, 9, could not possibly suit the Jewish without the Christian church.

Four beasts - Τεσσαρα ζωα· Four living creatures or four animals. The word beast is very improperly used here and elsewhere in this description. Wiclif first used it, and translators in general have followed him in this uncouth rendering. A beast before the throne of God in heaven sounds oddly.

It stands solid, calm, and clear, God's judgments are called "a great deep" (Ps 36:6). In Re 15:2 it is a "sea of glass mingled with fire." Thus there is symbolized here the purificatory baptism of water and the Spirit of all who are made "kings and priests unto God." In Re 15:2 the baptism with the fire of trial is meant.

And before the throne there was a sea of glass - An expanse spread out like a sea composed of glass: that is, that was pellucid and transparent like glass. It is not uncommon to compare the sea with glass. See numerous examples in Wetstein, in loco. The point of the comparison here seems to be its transparent appearance. It was perfectly clear - apparently stretching out in a wide expanse, as if it were a sea. Like unto crystal - The word “crystal” means properly anything congealed and pellucid, as ice; then anything resembling that, particularly a certain species of stone distinguished for its clearness - as the transparent crystals of quartz; limpid and colorless quartz; rock or mountain quartz. The word “crystal” now, in mineralogy, means an inorganic body which, by the operation of affinity, has assumed the form of a regular solid, by a certain number of plane and smooth faces. It is used here manifestly in its popular sense to denote anything that is perfectly clear like ice. The comparison, in the representation of the expanse spread around the throne, turns on these points: (1) It appeared like a sea - stretching afar. (2) It resembled, in its general appearance, glass; and this idea is strengthened by the addition of another image of the same character - that it was like an expanse of crystal, perfectly clear and pellucid. This would seem to be designed to represent the floor or pavement on which the throne stood. If this is intended to be emblematical, it may denote: (a) that the empire of God is vast - as if it were spread out like the sea; or. (b) it may be emblematic of the calmness, the placidity of the divine administration - like an undisturbed and unruffled ocean of glass. Perhaps, however, we should not press such circumstances too far to find a symbolical meaning. And in the midst of the throne - ἐν μέσῳ τοῦ θρόνου en mesō tou thronou. […]

In one of Stevenson's letters there is a characteristically humorous remark about the appalling impression produced on him in childhood by the beasts with many eyes in the Book of Revelations: "If that was heaven, what in the name of Davy Jones was hell like?" …