In the superscription of Psalm 12, the word sheminith, as in Psalm 6, is likely properly translated in the NKJV as "eight-stringed harp." As to substance, David in Psalm 12 laments the perversion of language he witnesses everywhere, with people using words to hurt each other. Conversation is filled with lies, flattery, deception, boasting, idle words (verses 2-4). "Everyone lies to his neighbor" (verse 2, NIV). The wicked say whatever promotes their own interests (verse 4). "We'll talk our way to the top, we'll outtalk the simple; no one can stop us" (Knight, Psalms, comments on Psalm 12:1-8). Christ warned his followers to be careful about what they say: "But I say to you that for every idle word men may speak, they will give account of it in the day of judgment. For by your words you will be justified, and by your words you will be condemned" (Matthew 12:36-37).

God doesn't speak meaningless, idle words. He backs up what He says. Therefore, when God states that He will rise up on behalf of the oppressed and provide a safe refuge (Psalm 12:5), the oppressed can confidently count on His help. "In contrast to the idle words of the wicked (vv. 1-4), the words of God are altogether trustworthy. The eternal and steadfast nature of the Lord Himself stands behind His words" (Nelson Study Bible, note on verses 5-7). The words of God here can denote the whole of Scripture. The comparison of refining silver demonstrates how carefully chosen His words are. That they are purified seven times demonstrates how complete and perfect they are. It may also hint at numerous patterns of seven, signifying completeness and perfection, within the Bible.

The psalm ends in verse 8 with the sobering reminder that though God will be faithful to His promises in taking care of His people, we still in the meantime must be on guard against the reality of living in an evil world.