Revelation 4:6

and before the throne, as it were a glassy sea like crystal; and, in the midst of the throne, and around the throne, four living creatures full of eyes before and behind.

Revelation 5:6

And I saw, in the midst of the throne and of the four living creatures, and in the midst of the elders, a Lamb standing, as if slain, having seven horns and seven eyes, which are the seven Spirits of God, sent forth into all the earth.

Revelation 15:2

And I saw as it were a glassy sea mingled with fire; and those who were victorious over the beast, and over his image, and over the number of his name, standing by the glassy sea, having harps of God.

Revelation 7:11

And all the angels stood around the throne, and around the elders, and the four living creatures; and they fell before the throne on their faces, and worshiped God,

Revelation 14:3

And they sing as it were a new song before the throne, and before the four living creatures and the elders; and no one was able to learn the song, except the hundred and forty-four thousand, who had been purchased out of the earth.

Revelation 15:7

And one of the four living creatures gave to the seven angels seven golden bowls, full of the wrath of God, who liveth forever and ever.

Revelation 19:4

And the twenty-four elders and the four living creatures fell down, and worshiped God, Who sitteth on the throne, saying, "Amen! Hallelujah!"

Revelation 4:8-9

And the four living creatures, having each one of them six wings, are full of eyes around and within; and they have no rest, day and night, saying, "Holy! Holy! Holy! the Lord God, the Almighty, Who was, and Who is, and Who is coming!"

Revelation 5:14-1

And the four living creatures said, "Amen." And the elders fell down and worshiped.

Revelation 7:17

because the Lamb, Who is in the midst of the throne, will be their Shepherd, and will guide them to the fountains of the waters of life; and God will wipe away every tear from their eyes.

Revelation 21:11

having the glory of God; her radiance was like a stone most precious, as a jasper stone clear as crystal;

Revelation 21:18

And the material of its wall was jasper; and the city was pure gold, like pure glass.

Revelation 21:21

And the twelve gates were twelve pearls; each one of the gates, severally, was of one pearl; and the street of the city was pure gold, as transparent glass.

Revelation 22:1

And he showed me a river of water of life, bright as crystal, issuing forth out of the throne of God and of the Lamb,

Treasury of Scripture Knowledge

Summary

And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind.

Bible References

A sea

Revelation 15:2
And I saw as it were a glassy sea mingled with fire; and those who were victorious over the beast, and over his image, and over the number of his name, standing by the glassy sea, having harps of God.

Crystal

Revelation 21:11
having the glory of God; her radiance was like a stone most precious, as a jasper stone clear as crystal;
Revelation 22:1
And he showed me a river of water of life, bright as crystal, issuing forth out of the throne of God and of the Lamb,

The midst

Revelation 5:6
And I saw, in the midst of the throne and of the four living creatures, and in the midst of the elders, a Lamb standing, as if slain, having seven horns and seven eyes, which are the seven Spirits of God, sent forth into all the earth.
Revelation 7:17
because the Lamb, Who is in the midst of the throne, will be their Shepherd, and will guide them to the fountains of the waters of life; and God will wipe away every tear from their eyes.

Four beasts

Revelation 4:8
And the four living creatures, having each one of them six wings, are full of eyes around and within; and they have no rest, day and night, saying, "Holy! Holy! Holy! the Lord God, the Almighty, Who was, and Who is, and Who is coming!"
Revelation 5:6
And I saw, in the midst of the throne and of the four living creatures, and in the midst of the elders, a Lamb standing, as if slain, having seven horns and seven eyes, which are the seven Spirits of God, sent forth into all the earth.
Revelation 6:1
And I saw, when the Lamb opened one of the seven seals, and I heard one of the four living creatures saying, as with a voice of thunder, "Come."
Revelation 7:11
And all the angels stood around the throne, and around the elders, and the four living creatures; and they fell before the throne on their faces, and worshiped God,
Revelation 14:3
And they sing as it were a new song before the throne, and before the four living creatures and the elders; and no one was able to learn the song, except the hundred and forty-four thousand, who had been purchased out of the earth.
Revelation 15:7
And one of the four living creatures gave to the seven angels seven golden bowls, full of the wrath of God, who liveth forever and ever.
Revelation 19:4
And the twenty-four elders and the four living creatures fell down, and worshiped God, Who sitteth on the throne, saying, "Amen! Hallelujah!"

Full

Revelation 4:8
And the four living creatures, having each one of them six wings, are full of eyes around and within; and they have no rest, day and night, saying, "Holy! Holy! Holy! the Lord God, the Almighty, Who was, and Who is, and Who is coming!"