Oil in the Bible represents the Lord’s love, so anointing someone (or something) with oil was a way to make that person (or object) a representative of the Lord. At the ultimate level, of course, the Lord Himself, as Jesus, is known as “the Anointed,” used with a similar meaning to “Messiah” or “Christ.” Being the Anointed means that he is love itself, presented to us through divinely true ideas. The fact that kings and priests were anointed meant that they also could represent true ideas coming from good loves, on a lower level.

(सन्दर्भ: Apocalypse Revealed 779 [2]; Arcana Coelestia 9954; The Apocalypse Explained 375 [7-25], 684 [2-33])

779. Since oil is mentioned here among sacred ingredients of worship, and symbolizes celestial good, we must say something now about the oil used in anointing, oil which was used by ancient peoples and afterward commanded to the children of Israel.

In ancient times people anointed stones set up as pillars, as is apparent from Genesis 28:18-19, 22. They also anointed weapons of war, shields and bucklers (2 Samuel 1:21, Isaiah 21:5). The Israelites were commanded to prepare holy oil with which to anoint all the sacred ecclesiastical vessels; and they used it to anoint the altar and all its vessels, as well as the Tabernacle and all its vessels (Exodus 30:22-33, 40:9-11; Leviticus 8:10-12; Numbers 7:1). They used it to anoint the men who exercised the functions of the priesthood and their garments (Exodus 29:7, 29, 30:30, 40:13-15; Leviticus 8:12; Psalm 133:1-3). They used it to anoint prophets (1 Kings 19:15, 16). They used it to anoint kings, and kings were called therefore Jehovah's anointed (1 Samuel 10:1, 15:1, 16:3, 6, 12, 24:6, 10, 26:9, 11, 16, 23; 2 Samuel 1:16, 2:4, 7, 5:3, 17, 19:21; 1 Kings 1:34, 35, 19:15, 16; 2 Kings 9:3; 11:12; 23:30; Lamentations 4:20; Habakkuk 3:13; Psalms 2:2, 6; 20:6; 28:8; 45:7; 84:9; 89:20, 38, 51; 132:17).

[2] Anointing with holy oil was commanded because oil symbolized the goodness of love and represented the Lord, who in His humanity is Himself Jehovah's anointed and His only anointed, being anointed not with oil, but with the Divine goodness itself of Divine love. Consequently He is also called the Messiah in the Old Testament and Christ in the New Testament (John 1:41; 4:25), Messiah and Christ meaning "the Anointed."

That is why priests, kings, and all ecclesiastical vessels were anointed, and having been anointed were called holy - not that they were holy in themselves, but because by virtue of the anointing they represented the Lord in His Divine humanity. Consequently it was a sacrilege to harm a king, because he was Jehovah's anointed (1 Samuel 24:6, 10; 26:9).

[3] Furthermore, it was an accepted practice to anoint themselves and others to attest to their gladness of heart and goodwill, but with ordinary oil or some other fine oil, and not with holy oil (Matthew 6:17; Mark 6:13; Luke 7:46; Isaiah 61:3; Amos 6:6; Micah 6:15; Psalms 92:10; 104:15; Daniel 10:3; Deuteronomy 28:40). They were not permitted to anoint themselves or others with holy oil (Exodus 30:31-33).