Ezekiel 27:12 - Matthew Poole's English Annotations on the Holy Bible

Tarshish; the city or country for the inhabitants; some say Carthaginians, others Tarsus in Cilicia; others with more probability say it is Tartessus, an ancient town on the mouth of the river Baetis; or rather, over against it, in an island, (where Gades, now Cadiz,) a convenient port to export the rich metals that were brought down the Baetis from the country abounding with them, and through which their Baetis ran, and the inhabitants of this Tartessus furnished the Tyrians with them. Spain was full of silver and iron; these were the product of the country. Tin; it is probable they fetched this from some islands over against the own country is most noted for tin and lead, which some say was fetched by the Phoenicians; if so, for aught I see to the contrary, the Tartessians, who were a people before ever the Tyrians came into those parts, might first trade here, and fetch it hence, and carry it to Tyre, the voyage being neither long or dangerous enough between that island and our Cornwall, to render the thing difficult or the conjecture improbable.