Boyd’s Bible Dictionary:

(resinous). A cone-bearing tree whose reddish fragrant wood was much prized (1 Kings 7:2; Psa. 92:12; Song of Sol. 5:15; Isa. 2:13; Ezek. 31:6).

Concise Bible Dictionary:

The beautiful tall tree that was extensively used by Solomon in building the temple and his palaces. It is called “cedar” from the firmness of its roots; its wood is very durable and odoriferous. It was used for beams, pillars and masts, and for carved images (1 Kings 6:9-10; Isa. 44:14; Ezek. 27:5). Special reference is made to it in scripture, as “the trees of the Lord are full of sap; the cedars of Lebanon which he hath planted” (Psa. 104:16). It cannot be considered as one of the trees of Palestine proper, but is constantly connected in scripture with Lebanon, where it still grows in a group of some 300, a few being very old, and with no others near: the neighboring people regard them with reverence.
In the cleansing of the leper, and in connection with burning the Red Heifer, cedar wood and hyssop were used, typical of the highest and the lowest—the judgment of death upon all men and the whole fashion of this world (Lev. 14:4-52; Num. 19:6). The cedar is used as a symbol of strength and stability: the righteous shall grow up as a cedar of Lebanon (Psa. 92:12). The Assyrian king in his strength was also compared to a cedar, which is thus described: “with fair branches, and with a shadowing shroud, and of an high stature” (Ezek. 31:3); for his pride he was to be brought down.