Psalm 12 contrasts the flattering words (:2-3) and boastful word-faith (:4) of men with the perfect words of God. Verse 6 says “The words of the LORD are pure words; as silver tried in a furnace on the earth, refined seven times.”
Here we find a 3-fold emphasis on the purity of God’s word:

— First, it says (literally) “the sayings of God (are) pure sayings”. “Pure” means uncorrupted by evil or falsehood.

— Next, it says that His words are “like silver refined by fire on the earth”. Just as silver is pure, having had its impurities removed by the refining fire, so God’s words have no impurity in them.

— Then, it adds: “purified 7 times.” “7” is a number which signifies perfection in the Bible, so what it is affirming is that God’s word is ultimately pure and perfect.

This 3-fold repetition of the teaching of the purity of God’s word emphasizes that the words of God contained in scripture are “totally true and trustworthy” and “truth without any mixture of error.” (The Baptist Faith & Message, 2000). The words of men can and will fail us or deceive us, but you can trust your life — and even your eternal soul — on the perfect and trustworthy word of God!