to refine by drawing off what is impure: to bring gold, silver, wine, or water to a clean state by taking out of it whatever does not belong
This is a workshop word, and the picture behind it is narrow and physical: something is put through a process that draws off whatever does not belong, and what is left is clean. It is rare, seven times in the whole Hebrew Bible, and every one of those sits in poetry, prophecy, or the temple inventories, where a writer wanted a word for purity that had actually been worked for.
The same verb stretches across four materials, which is what makes it worth noticing:
- gold and silver brought to full purity for the furnishings of the temple
- wine drawn off the sediment it has been resting on, so that it pours clear
- rain filtered out of the mist and let down in drops
- and, once, the priests of Israel put through what the metal goes through
Two other refining words sit close by, and two passages use them side by side with this one. The smelter's word (צָרַף) is about the fire itself, heating ore until the dross burns off and the metal is proved genuine, and it is the word the prophets most often turn on people. A third word (טָהֵר) names the finished state of being clean, above all clean enough for worship. This one sits between them: not the fire, and not the verdict, but the actual removal of the impurity.
Because the picture is so concrete, the two figurative uses land hard. When Psalm 12:6 calls the words of the LORD silver purified seven times, the claim is that nothing is left in them that could fail. When Malachi 3:3 says the LORD will refine the sons of Levi, he means the priesthood will go through exactly what silver goes through.