'A sandal tree' signifies aspects of the natural self.

(References: Apocalypse Explained 518)

104. (Verse 4) Nevertheless I have against thee, that thou hast left thy first charity. That this signifies that they do not make such a life as pertains to those who live in the beginning of the church the essential of knowledges (cognitiones), is evident from the signification of first charity, as being a life according to the knowledges of good and truth, such as pertains to those who are in the beginning of the church (concerning which we shall speak presently), and from the signification of leaving that charity, as being that it is not made the essential of knowledges. For those who study the knowledges of truth and good, and believe that they shall be saved by means of them, make knowledges and not life the essential, although a life according to knowledges is the essential. But as this essential of the church and of salvation is treated of in what now follows, more shall be said concerning it. The reason why charity denotes life, is, because all life according to the precepts of the Lord in the Word is called charity; wherefore to exercise charity is to live according to those precepts. (That this is the case may be seen in The Doctrine of the New Jerusalem, in the article concerning, love towards the neighbour, or charity, n. 84-106; and in the small work, The Last Judgment 33-39.) The life of the church in its commencement is here meant by first charity, for every church begins from charity, and declines successively from it to faith alone, or to merit-seeking works. (Concerning this matter, and concerning charity, see what is said in Arcana Coelestia, namely, that every church commences from charity, but that in process of time it declines from it, n. 494, 501, 1327, 3773, 4689; and thus to falsities from evil, and at length to evils, n. 1834, 1835, 2910, 4683, 4689; commonly to faith alone, n. 1834, 1835, 2231, 4683, 8094. A comparison of the beginning and the decline of the church with the rising and setting of the sun, n. 1837; and with the infancy and old age of man, n. 10134. That the church is not in man until the knowledges of good and truth are implanted in the life, 3310; that charity constitutes the church, n. 809, 916, 1798, 1799, 1844, 1894; that the internal of the church is charity, n. 4766, 5826; that the church would be one, and not many as at this day, if all were regarded from charity, although they may differ as to doctrinals of faith, and as to rituals of worship, n.1286, 1316, 1798, 1799, 1834, 1844, 2385, 2982, 3267, 3451; that the worship of the Lord consists in a life of charity, n. 8254, 8256: that the quality of worship is according to the quality of charity, n. 2190.)