Boyd’s Bible Dictionary:
A tree of the pine family
(2 Sam. 6:5; 1 Kings 5:8; Song of Sol. 1:17).
Concise Bible Dictionary:
This is supposed to be one of the conifers, but the species alluded to is not known. It came from Lebanon, and was used in the construction of houses, and for musical instruments (2 Sam. 6:5; 1 Kings 5:8, 10; 1 Kings 6:15, 34; 2 Chron. 2:8; 2 Chron. 3:5). It will be produced instead of the thorn in the millennium, and Israel, when she returns in blessing, will say, "I am like a green fir-tree" (Isa. 55:13; Hos. 14:8).