Morrish Bible Dictionary - Tarshish,
Tharshish
Place to which ships were sent from Palestine. It is supposed by some to refer to a Spanish city named Tartessus. This would appear a suitable place from whence to obtain silver, iron, tin, and lead. Jonah taking a ship at Joppa to sail to Tarshish may also indicate a place to the west of Palestine. But other passages refer to apes and peacocks, also being brought by ships of Tarshish, and these are associated with Ezion-geber, on the Gulf of Akaba, a branch of the Red Sea. It is therefore probable that the ships from this port would sail southward to some other place, which has not been identified. 1 Kings 10:22 ; 1 Kings 22:48 ; 2 Chronicles 9:21 ; 2 Chronicles 20:36,37 ; Psalm 48:7 ; Psalm 72:10 ; Isaiah 2:16 ; Isaiah 23:1-14 ; Isaiah 60:9 ; Isaiah 66:19 ; Jeremiah 10:9 ; Ezekiel 27:12,25 ; Ezekiel 38:13 ; Jonah 1:3 ; Jonah 4:2 .