A fir tree signifies the natural principle as to good. The fir tree, pine tree, and the box tree, as in Isaiah 60:13, signify the celestial natural things of the Lord's kingdom and church, consequently, such things as relating to external worship. A fir tree also signifies natural truth superior. A fir tree, as in Ezekiel 31:8, signifies the perception of the natural man.

(References: Arcana Coelestia 4014)