'Refined' in the Bible

The words of the Lord are pure words,like silver refined in an earthen furnace,purified seven times.

For You, God, tested us;You refined us as silver is refined.

until the time his prediction came true, as the word of the LORD refined him.

Therefore I love Your commandments more than gold,Yes, more than refined gold.

Your word is very pure (refined);Therefore Your servant loves it.