Revelation 4:6

And before the throne there was a sea of glass like unto crystal. — There is a sea before the throne of God. The woman apparelled in purple splendour sits upon many waters (Revelation 17:1). The waters are explained (Revelation 17:15) to be “peoples, and multitudes, and nations, and tongues.” Her throne rests on the fickle and stormy sea of world- opinion, fashion, and passion. The waters represent the unguided, unreasoning, and unprincipled thoughts of men. By analogy, the calm glass-like sea, which is never in storm, but only interfused with flame (Revelation 15:2), represents the counsels of God, those purposes of righteousness and love, often fathomless, but never obscure; always the same, though sometimes glowing with holy anger (Revelation 15:1). (Comp. the Psalmist’s words, “Thy judgments are like the great deep,” Psalms 36:6, Prayer Book version. See also Psalms 77:19, and Romans 11:33.) The position of the crystal sea is analogous to that of the molten sea in front of Solomon’s Temple (2 Chronicles 4:9).

And in the midst of the throne — i.e., between the seer and the throne. The Apostle saw the crystal sea, and beyond it the living creatures encircling the throne — four living creatures (or, living beings) full of (or, teeming with) eyes before and behind.