Albert Barnes Commentary 1 Kings 10:12

"And the king made of the almug-trees pillars for the house of Jehovah, and for the king`s house, harps also and psalteries for the singers: there came no such almug-trees, nor were seen, unto this day." — 1 Kings 10:12 (ASV)

Pillars - The Hebrew word ordinarily signifies a “prop,” as a marginal note suggests. In this context, it is generally thought to mean a “railing” or “balustrade.” This meaning connects and harmonizes the passage with the parallel account in Chronicles, where Solomon is said to have made “stairs” from the almug wood for the temple and for his own house.

Harps - The Jewish harp, the כנור (kı̂nnôr), was triangular and ordinarily had ten strings. It probably resembled the ancient Assyrian harp, which was played with a plectrum, as the “kinnor” ordinarily was.

Psalteries - The psaltery, or viol—in Hebrew, נבל (nebel); in Greek, νάβλα (nabla)—was a stringed instrument played by hand. It may have been a lyre, like those seen on Hebrew coins, with a sounding board shaped like a jug. Alternatively, it could have been a type of guitar with a hollow, jug-shaped body at its lower end.