Often portable, Genesis 15:17 . They were used for melting the precious metals, Proverbs 17:3 . The furnace into which Daniel's three friends were cast was large, and remained open after they were cast in, Daniel 3:1-30 . The fearful punishment spoken of in Jeremiah 29:22 is still used in the East. The word furnace is used to illustrate a state of oppression, Deuteronomy 4:20 , and of affliction, Isaiah 48:10 .