In Ezekiel 26:11, this signifies the love of learning or intellectual things. (Arcana Coelestia 3727)

In Revelation 6:2, this signifies the love of understanding the Word. (Apocalypse Revealed 298)

In Zechariah 12:4, this signifies that the intellectual should be filled with falsities. (Arcana Coelestia 2383[2])

In general, 'a horse' signifies knowledge or understanding of the Word. In an opposite sense it signifies the understanding of the Word falsified by reasonings, and likewise destroyed from self-derived intelligence. 'A dead horse' signifies no understanding of truth from the Word.

657. Verse 9. And they of the peoples and tribes and tongues and nations shall see, signifies with all who are in the falsities and evils of religion, of doctrine, and of life. This is evident from the signification of "to see," as being to know, to perceive, and to understand; also from the signification of "peoples and tribes" as being those who are in the falsities of doctrine and religion; "peoples" in the Word mean all who are in truths or in falsities, whether they are of the church or of some religion out of the church (See n. 175, 331, 625); and "tribes" mean in the Word all who are in truths or in falsities of doctrine, for "tribes" signify all truths and falsities of doctrine (See above, n. 330, 430, 431, 454). From this it can be seen that "peoples and tribes" signify all who are in the truths or falsities of religion and of doctrine, here those who are in falsities, because it is said, "they shall see the bodies of the witnesses three days and a half, and shall not suffer them to be placed in sepulchers." This is evident also from the signification of "tongues and nations," as being those who are in the evils of doctrine and of life, for "tongues" signify the goods or evils of doctrine, and thence of religion (See above, n. 330, 455, 625); and "nations" signify the goods or evils of life (See also above, n. 175, 331, 625); from which it can be seen that "tongues and nations" signify all who are in the goods or the evils of doctrine and of life, here those who are in the evils, since it is said of them that "they shall see the bodies of the witnesses upon the street of the great city, and shall not suffer them to be placed in sepulchers."