Charles Ellicott Commentary Jeremiah 10:9

"There is silver beaten into plates, which is brought from Tarshish, and gold from Uphaz, the work of the artificer and of the hands of the goldsmith; blue and purple for their clothing; they are all the work of skilful men." — Jeremiah 10:9 (ASV)

Tarshish. —As elsewhere in the Old Testament, Spain, the Tartessus of the Greeks (Genesis 10:4; Jonah 1:3; Ezekiel 27:12), from where Palestine, through the Phoenicians, was chiefly supplied with silver, tin, and other metals.

Uphaz. —Possibly an error of transcription, or dialectical variation, for Ophir, giving the meaning “gold-coast.” The word is found only here and in Daniel 10:5. Some interpreters, however, connect it with the name of Hyphasis, one of the tributaries of the Indus. We cannot attain to greater certainty. (See Note on 1 Kings 9:28.)

Blue and purple. —Both were colors obtained from the murex, a Mediterranean shellfish, and were used both for the curtains of the Tabernacle (Exodus 25:4) and for the gorgeous apparel of the idols of the heathen. “Purple,” as elsewhere in the English of the Bible, must be understood as a deep crimson or scarlet. (Mark 15:17.)