'Refine' in the Bible

"There are still too many soldiers," the LORD told Gideon. "Bring them down to the water and I'll refine them for you there. Therefore when I say to you, "This one will be going with you,' he'll go with you, but no one may go about whom I tell you, "This one won't be going with you.'"

When you probe my heart, and examine me at night; when you refine me, you will find nothing wrong, for I have determined that I will not transgress with my mouth.

When I turn my attention to you, I'll refine your dross as in a furnace. I'll remove all your alloy.

Therefore, this is what the LORD of the Heavenly Armies says: "Look, I'm about to refine and test them. Because they're my people, what else can I do?