A body of water in the vision of heaven described by John in the book of Revelation (Rv 4:6). It appears again later, in a different vision (15:2), and is perhaps connected with other “sea” references in the same book (13:1; 21:1). It probably depicts the vast expanse before God’s throne. The crystal clearness of this sea may symbolize that everything is translucent and revealed in the presence of God.
Sea of Glass
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.