Silver

Dictionary of Biblical Words:

is typical of redemption, being the redemption money of the Israelites. The words of the Lord, the tongue of the just, saints in affliction, are all compared to silver (Psa. 12:6; Prov. 10:20; Isa. 1:22; Psa. 66:10).

Boyd’s Bible Dictionary:

(white). Used by Hebrews from earliest times for money, vessels, and ornaments, but not in form of coins till after the captivity ({vi 321;645;1327}Gen. 13:2; 24:53; 44:2; Job 28:1; Matt. 26:15; Acts 19:24). Silver supplied to Jerusalem from Arabia and Tarshish ({vi 11379;11386}2 Chron. 9:14,21).

Concise Bible Dictionary:

Silver Ruble
This was a source of wealth from early days. Abraham was rich in silver (Gen. 13:2); but with Solomon gold was so plentiful that silver was “nothing accounted of” (1 Kings 10:21). The silver and gold which he had amassed were, alas, afterward carried away to enrich their enemies because of the sins of Israel (2 Chron. 12:9). Silver was also the common specie of commerce, “pieces of silver” being weighed long before money was coined (Gen. 23:16). Silver was used for the sockets, hooks, etc., in the tabernacle, the money paid for the redemption of the Israelites being applied to this purpose ({vi 2394-2399}Ex. 30:11-16; {vi 2659-2662}Ex. 38:25-28). The house of God is founded on redemption ({vi 2591-2603}Ex. 36:24-36; {vi 2644-2651}Ex. 38:10-17).
Silver is found in the earth (Job 28:1), and before it can be compared to “the words of the Lord” it must be purified seven times (Psa. 12:6; Prov. 25:4).
Silver
THE SILVER CORD in Ecclesiastes 12:6 seems to refer to the thread of life, which is loosed, or removed, when death ensues.