These two types of wood were the finest, most sought after types of wood available in the days of Isaiah. The cedars of Lebanon were used to build the temple of Solomon (1 Kings 5:6). In this scripture these two types of timber represent the fine things in the world, royal authority, and the pride and loftiness of man’s materialism. Zechariah similarly describes the trees of the forest as representing pride—a pride that will be destroyed when the Lord is exalted:
’Open thy doors, O Lebanon, that the fire may devour thy cedars.
Howl, fir tree; for the cedar is fallen; because the mighty are spoiled: howl, O ye oaks of Bashan; for the forest of the vintage is come down.
There is a voice of the howling of the shepherds; for their glory is spoiled: a voice of the roaring of young lions; for the pride of Jordan is spoiled.’ (Zech 11:3)
“The cedar is often figuratively alluded to in the sacred Scriptures. ’The mighty conquerors of olden days, the despots of Assyria and the Pharaohs of Egypt, the proud and idolatrous monarchs of Judah, the Hebrew commonwealth itself, the war-like Ammonites of patriarchal times, and the moral majesty of the Messianic age, are all compared to the towering cedar, in its royal loftiness and supremacy.’ (Easton’s Bible Dictionary, ”Cedar")
Hugh Nibley
“But you can find about half a dozen cedars of Lebanon today. In a few little pockets where they‘ve been preserved you’ll find a cedar. They’ve sprung up, and there may be a hundred or two in the land. That’s about all there are. You can’t find [many] cedars of Lebanon. It has been bare ever since, but at one time [Lebanon] supplied the world with all the timber it needed for thousands of years.” (Teachings of the Book of Mormon, Lecture 74, p. 209)