Ancient metal workers would remove the pure silver and gold from their impurities by heating the metal until it was in liquid form (gold melts at 1,945 degrees F and silver at 1,761 degrees F).
Often the metal workers would use a clay oven with 2 small openings in the bottom (one for blowing/fanning/bellowing the flame, and the other for pouring out the metal). This refining process made it possible to identify and remove the impurities from the gold and silver.
The Word of the Lord is pure like metal refined in these ways (see Psalm 12:6).

Proverbs 17:3 speaks of the “crucible” (Heb. masrep) being used to test the purity of silver and a melting oven (Heb. sarap) for testing the genuineness of gold with the process of cupellation.  In the second half of the Proverbs 17:3, God is the one who tests the human heart. The Lord testing the heart is also seen in Proverbs 21:2 and 24:12 and Psalm 17:3; 66:10).

The good news is that the Lord is not merely testing us and finding the weaknesses in our character
and the flaws in our nature so he can judge us. The use of the crucible and the furnace as
illustrations of the Lord’s work indicates God is also interested in helping us get rid of these weaknesses and flaws just like the metal worker does with gold and silver. The Lord is not just
in the process of judging us, but is in the process of purifying us.  

This is seen in these verses using the refining of metal as an illustration:

• Isaiah 1:24-26
• Isaiah 48:10 - while using the "furnace of affliction"
• Jeremiah 9:7
• Jeremiah 6:29
• Daniel 11:35
• Zechariah 13:8-9

Besides the Lord testing us and refining us one of the most important steps in this process is our participation. We have to be willing to remove the impurities or the dross. As the Lord says to Jeremiah, we must be willing to repent for the process to be completed.

“Therefore this is what the Lord says:
‘If you repent, I will restore you that you may serve me;
if you utter worthy, not worthless, words, you will be my spokesman.
Let this people turn to you, but you must not turn to them.’ ”
- Jeremiah 15:19

In Psalm 139:23-24 David asks to know his imperfections, because he can only remove the impurities and the flaws that he can see.

If we do not repent and willingly remove the impurities then the Lord will be bellowing (fanning the flame) and refining us in vain as is described in Jeremiah 6:29-30:

"The bellows blow fiercely to burn away the lead with fire,
but the refining goes on in vain; the wicked are not purged out.
They are called rejected silver, because the Lord has rejected them.”

The Hebrew word Messiah means “to smear, or anoint” and is simply called the “Anointed One” by Daniel. The Greek word for “the anointed one” is christos or, in English, “Christ”. The word Christ means “the anointed one”, or the Messiah.