Revelation 15:2

“And I saw, as it were, a sea of glass mingled with fire, etc.] Not baptism, but rather the blood of Christ, which may be compared to a sea, for its abundant virtue and efficacy in cleansing from all sin; and to a sea “of glass”, since in it are clearly seen free justification, full pardon, peace and reconciliation; and may be said to be “mingled with fire”, being attended in the application of it with the Spirit of God, whose gifts and graces are sometimes signified by fire: and so, according to others, this sea may represent the pure church of God, as washed in the blood of the Lamb; compared to a sea for the multitude of which it consists, and to a sea of glass, because of the transparency…”

“sea of glass--Answering to the molten sea or great brazen laver before the mercy seat of the earthly temple, for the purification of the priests; typifying the baptism of water and the Spirit of all who are made kings and priests unto God. mingled with fire--answering to the baptism on earth with fire, that is, fiery trial, as well as with the Holy Ghost, which Christ's people undergo to purify them, as gold is purified of its dross in the furnace. them that had gotten the victory over--Greek, "those (coming) off from (the conflict with) the beast-conquerors." over the number of his name--A, B, C, Vulgate, Syriac, and Coptic omit the words in English Version, "over his mark." The mark, in…”

“And I saw as it were a sea of glass - In Revelation 4:6, a similar vision is recorded - “And before the throne there was a sea of glass, like unto crystal.” See the notes on that passage. The sea of glass here means a sea clear, pellucid, like glass: an expanse that seemed to be made of glass. There it was entirely clear; here it is mingled with fire. Mingled with fire - That is, a portion of the sea was red like fire. It was not all clear and pellucid, as in Revelation 4:6, but it was as it were a tesselated expanse, composed in part of what seemed to be glass, and in part of a material of a red or fiery color. In the former case Revelation 4:6, the emblem was designed to represent the pure…”

“The song was sung while the angels were coming out, with their plagues, who are therefore mentioned both before and after it, Rev 15:1-6. And I saw as it were a sea of glass mingled with fire - It was before "clear as crystal," Rev 4:6, but now mingled with fire, which devours the adversaries. And them that gained, or were gaining, the victory over the wild beast - More of whom were yet to come. The mark of the beast, the mark of his name, and the number of his name, seem to mean here nearly the same thing. Standing at the sea of glass - Which was before the throne. Having the harps of God - Given by him, and appropriated to his praise. Revelation 15:3”

“15:2 The glass sea mixed with fire symbolizes victory through testing. Those who had been victorious over the beast (see 13:1-8, 15-18) hold harps that represent ultimate peace. Their place on the glass sea (cp. 4:6) symbolizes their endurance in the fire of persecution (cp. Ps 66:12; Isa 43:2; Dan 3:8-30).”

“a sea: Rev 4:6, Rev 21:18 mingled: Isa 4:4, Isa 4:5; Mat 3:11; Pe1 1:7, Pe1 4:12 that had: Rev 11:11, Rev 11:12, Rev 12:11, Rev 13:14-18, Rev 14:1-5 stand: Eze 22:30, Eze 22:31 having: Rev 5:8, Rev 14:2, Rev 19:1-7 Revelation 15:3”