916. Verse 21. And the twelve gates were twelve pearls; each one of the gates was of one pearl, signifies that the acknowledgment and knowledge of the Lord, conjoins into one all the knowledges of truth and good, which are from the Word, and introduce into the church. By "the twelve gates" are signified the knowledges of truth and good in a summary, by which man is introduced into the church (n. 899, 900). By "twelve pearls" is also signified the knowledges of truth and good in a summary (n. 727), hence it was that "the gates" were "pearls;" the reason why "each of the gates was of one pearl" is because all the knowledges of truth and good, which are signified by "gates" and by "pearls," have relation to one knowledge; which is their containant, which one knowledge is the knowledge of the Lord. It is called one knowledge, although there are many which constitute that one knowledge; for the knowledge of the Lord is the universal of all things of doctrine and thence of all things of the church; from it all worship derives its life and soul, for the Lord is the all in all of heaven and the church, and thence in all things of worship.
 The reason why the acknowledgment and knowledge of the Lord conjoins into one all the knowledges of truth and good from the Word, is because there is a connection of all spiritual truths, and if you will believe it, their connection is like the connection of all the members, viscera, and organs of the body; wherefore as the soul contains all these in their order and connection, so that they are felt no otherwise than as one, so, in like manner, the Lord holds together all spiritual truths with man. That the Lord is the very gate, by which men are to enter into the church and thence into heaven, He Himself teaches in John:
I am the door; by Me if anyone enter in, he shall be saved (John 10:9).
And that the acknowledgment and knowledge of Him is the pearl itself, is meant by these words of the Lord in Matthew:
The kingdom of the heavens is like unto a merchant seeking beautiful pearls, who when he had found one precious pearl, went and sold all that he had, and bought it (Matt. 13:45-46).
"One precious pearl" is the acknowledgment and knowledge of the Lord.