When a product is pure, unadulterated, it produces the results for which it was created. Without fillers, its effect is more powerful. Purity means potency, value, and consistency.
The LORD’s words are absolutely reliable.
They are as untainted as silver purified in a furnace on the ground,
where it is thoroughly refined.
Psalm 12:6 NET
In this psalm, the word of the Lord is the answer to the prayer of the faithful, who are surrounded by the falsehoods of the wicked. The word is a promise of security and salvation.
Like refined silver, the word of God has been tested repeatedly. God fulfills his promise. Always.
“With God truth and reality do not differ” (Artur Weiser, The Psalms: A Commentary [Westminster John Knox Press, 2000]: 160).