'Crucible' in the Bible

The words of Yahweh [are] pure words [like] silver refined in the crucible on the ground, refined seven times.

A crucible [is] for the silver, and a furnace [is] for the gold, but Yahweh will test hearts.

A crucible [is] for the silver, and a furnace for the gold, but a man [is tested by] the mouth of him who praises him.