Psalms 12:6 The words of the LORD are pure words, as silver tried in a crucible on the earth, refined seven times. (JPS)
Proverbs 17:3 The heating-pot is for silver and the oven-fire for gold, but the Lord is the tester of hearts. (See RSV NIV)
Proverbs 27:21 The crucible is for silver, and the furnace for gold; but man is refined by his praise. (WEB NAS RSV NIV)