661. Standing beside the sea of glass, having harps of God. This symbolizes the Christian heaven at the boundaries [of the spiritual world], and the faith accompanying charity in the people there.

Since the sea of glass symbolizes a gathering of people who have religion and worship indeed, but lack any goodness of life (no. 659), therefore those whom John saw standing beside that sea symbolize the Christian heaven at its boundaries, consisting of people who have religion and worship and possess goodness of life, because they had the victory over the beast and over its image.

A higher Christian heaven was the subject of the preceding chapter. Those of whom that heaven was formed are meant by the one hundred and forty-four thousand whom John saw standing with the Lamb on Mount Zion, as explained in nos. 612-625. Their harps symbolize a confession of the Lord in consequence of spiritual truths (nos. 276, 616). Spiritual truths are those of a faith springing from charity.

[2] John's seeing the people with harps and hearing them sing a song, as we are told next, was a representational depiction of a confession stemming from a faith accompanying charity. The affections in the thoughts of angels in heaven and the consequent intonations in their speech are heard in various ways in the spiritual world below, either as the sound of water, or as the sound of thunder, as in chapter 14:2 above. Or it may be heard as the sound of trumpets, as in chapter 4:1 above. Or, as in the present case, as the sound of harps, as also in chapter 5:8; 14:2. But still, it is not the sound of water, nor the rumbling of thunder, nor the sounding of a trumpet or harp; indeed, it is not the sound of singing. Rather it is the speech of angels and their confessions in accordance with their affections and consequent thoughts that are thus heard below, from which one may perceive the character of their love and wisdom.

The ways angels' speech is heard is due to the correspondence of affection with sound and of thought with speech.