931. (Verse 2) And I saw as it were a glassy sea, mingled with fire. That this signifies the generals of truth in the Word pellucent from spiritual truths, that are from the good of love, is evident from the signification of a glassy sea, as denoting generals of truth pellucent from spiritual truths (concerning which see above, n. 275); and from the signification of fire, as denoting the good of love (see n. 68, 496, 504, 916).

It shall be here briefly explained why a glassy sea signifies the generals of truth in the Word pellucent from spiritual truths. By sea are signified truths in general because waters, fountains, and rivers, signify truths from which intelligence is derived, the sea being their general receptacle. Truths in general, or the generals of truth, are such as are in the sense of the letter of the Word, and this is natural; and everything natural is a general receptacle of spiritual things. For there is nothing in nature, or what is natural, that does not exist from what is spiritual; for what is natural has been formed from what is spiritual, as an effect from its efficient cause. And because thus a thousand spiritual things effect and form one natural thing, therefore this one, as being the containant of a thousand, is general.

[2] Such also is the Word in the sense of the letter relatively to the Word in the spiritual sense. And because the spiritual sense of the Word is in the natural sense, and is therein pellucent before the angels; therefore the Word, as to generals of truth pellucent from spiritual truths, is signified by a glassy sea. The meaning of a glassy sea is similar elsewhere in the Apocalypse:

"And in the sight of the throne, a glassy sea like to crystal" (4:6).

Also:

The city New Jerusalem, likewise the street of the city, were seen "As pure gold, like pellucid glass" (21:18, 21).

For by that city is signified the doctrine of the church; and by street, the truth of that doctrine; and the truths of that doctrine, because they are genuine, derive their light and thence their clearness from spiritual truths. This clearness is what is signified by glass and by crystal. Also:

"The expanse over the heads of the cherubs was seen like the appearance of a wonderful crystal" (Ezekiel 1:22),

signifies the spiritual Divine in heaven. That by the glassy sea is signified the Word in the sense of the letter, pellucent from its spiritual sense, is also evident from this, that near it were seen those who had the victory over the beast; and by them are signified those who have not falsified the Word, and have not, by that means, extinguished the light of the spiritual sense.